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Institute of Medicine (US) Committee on Community-Based Drug Treatment; Lamb S, Greenlick MR, McCarty D, editors. Bridging the Gap between Practice and Research: Forging Partnerships with Community-Based Drug and Alcohol Treatment. Washington (DC): National Academies Press (US); 1998.

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Bridging the Gap between Practice and Research: Forging Partnerships with Community-Based Drug and Alcohol Treatment.

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DThe Treatment of Addiction: What Can Research Offer Practice?

A. Thomas McLellan and James R. McKay

Penn-VA Center for Studies of Addiction and The Treatment Research Institute at the University of Pennsylvania


Problems of substance dependence produce dramatic costs to society in terms of lost productivity, social disorder and of course health care utilization (NIDA, 1991; Merrill, 1993). Over the past twenty years many of the traditional forms of substance abuse treatment (e.g., methadone maintenance, therapeutic communities, outpatient drug free and others) have been evaluated multiple times and shown to be effective (Ball and Ross, 1991; DATOS, 1992; Hubbard et al., 1986, 1997; IOM, 1989, 1990b; McLellan et al., 1980; Simpson, 1981, 1997; Simpson et al., 1997a,b). Importantly, this research has shown that the benefits obtained from addiction treatments typically extend beyond the reduction of substance use, to areas that are important to society such as reduced crime, reduced risk of infectious diseases, and improved social function (Ball and Ross, 1991; Institute of Medicine, 1989, 1990b; McLellan et al., 1980). Finally, research findings indicate that the costs associated with the provision of substance abuse treatment provide 3- to 7-fold returns to the employer, the health insurer, and to society within approximately three years following treatment (Everingham and Rydell, 1994; Gerstein et al., 1994; Holder et al., 1991; IOM, 1990b; OTA, 1983; State of Oregon, 1996).

How Do These Research Results Translate into Recommendations that Can Be Useful for Treatment Providers?—Although the conclusions from reviews of the recent treatment research literature are important and gratifying, they are not adequate to inform important clinical questions regarding the delivery of substance abuse treatment services. Simply knowing that those who stay in treatment longer have better outcomes does not help when the funding and duration of treatment in ''real world" settings is regularly reduced (McLellan et al., 1996a). Further, research demonstrating that highly specialized and resource-intensive treatments "work" with highly selected samples of patients may not be helpful to "real world" treatment providers who have no prospects of accessing those treatments and whose caseloads contain very few of the patients on whom the specialized treatment was tested. This is particularly true at the level of the "community-based" public sector treatment programs that have been forced to operate under limited budgets with little access to sophisticated services. How can research in the treatment setting inform these providers? How can these providers use information from research studies to upgrade or expand their treatment efforts—within the practical constraints of budget and personnel available?

Parameters of the Literature Review—In response to these questions, we have reviewed the existing treatment outcome literature to summarize the available knowledge regarding the important patient and treatment factors that have been shown to influence the outcomes of addiction rehabilitation treatments. We felt this was an important first step in recognizing and recommending proven, practical, and cost-effective treatment strategies that can be implemented by community behavioral treatment programs. In this regard, we have elected not to review literature on detoxification methods in order to better focus on standard rehabilitation treatments for drug and alcohol dependence—typically following detoxification. Our review does not include the adolescent drug abuse treatment literature since it is still a developing field and there is a paucity of pertinent outcome studies in this area. In addition, we elected not to include a review of the smoking cessation literature as there have been excellent recent reviews of this entire field (see Fiore et al., 1996).

From a methodological perspective, we included only those clinical trials, treatment matching, or health services studies where the patients were alcohol or drug dependent by contemporary criteria (e.g., DSM); where the treatment provided was a conventional form of rehabilitation (any setting or modality); and where there were measures of either treatment processes or patient change during the course of treatment as well as posttreatment measures of outcome as defined later in the chapter. We have elected to include methadone maintenance (as well as its long acting form, levo-alpha-acetylmethadol [LAAM) as part of the general category of outpatient rehabilitation treatments, rather than create a special category.

In the review that follows we first discuss some of the basic assumptions underlying rehabilitation forms of addiction treatment since they set the stage for the clinical methods currently in use and for the types of studies that are in the research literature. Next we discuss some of our considerations regarding definitions of "outcome." With these assumptions and considerations in mind, we then review the most significant patient and treatment process contributors to the outcomes of addiction treatment.


What Is Addiction Rehabilitation Designed to Do?—In contrast to "detoxification," which is a relatively brief, usually medical procedure designed to stabilize the acute physical and emotional distress and instability caused by recent termination of heavy alcohol and/or drug use, "rehabilitation" is a much longer process, usually involving multiple types of medical and social services, that is designed to help recently stabilized patients achieve sustained periods of drug-free living and stable personal and social function.

There are clear physical signs and symptoms associated with the cessation of most addictive substances and there are standard medications and withdrawal procedures that are very effective in ameliorating these acute "detoxification" symptoms and restoring physiological and emotional stability. Despite the efficacy of these detoxification methods, there is uniform agreement among professionals that detoxification by itself—regardless of the type or the duration—is rarely associated with sustained periods of abstinence or even improved function. Well after the return of physiological and emotional stability, most patients continue to experience regular periods of intense craving for alcohol and drugs and this can lead to "loss of control" in situations where these drugs of abuse are (or have been) present. There has been substantial research showing that among former addicts who have been abstinent for up to a year, even the sight or sound of stimuli associated with former periods of drug use can produce (through learned association) measurable changes in brain chemistry that mimic the actual use of the drug and the withdrawal symptoms produced by those drugs (see Childress et al., 1985, 1986, 1992; O'Brien et al., 1991).

Rehabilitation Methods—While there is universal agreement that some form of rehabilitation is necessary, there has been a very wide range of professional opinion regarding the nature or amount of rehabilitation necessary to produce sustained benefits. In part this is due to disagreement regarding the etiology and course of the addiction syndrome. These etiological theories include a genetic predisposition, an acquired metabolic abnormality, learned negative behavioral patterns, self medication of underlying psychiatric or physical medical problems, and lack of family and community support for positive function. For this reason, there is an equally wide range of treatment methods that have been applied to address these etiological and predisposing factors and to provide continuing support for the targeted behavioral changes. These have included such diverse elements as psychotropic medications to relieve underlying psychiatric problems, "anti-craving" medications to relieve alcohol and drug craving, acupuncture to correct acquired metabolic imbalances, educational seminars, films and group sessions to correct false impressions about alcohol and drug use, group and individual counseling and therapy sessions to provide insight, guidance and support for behavioral changes, and peer help groups (AA/ NA/CA) to provide continued support for the behavioral changes thought to be important for sustaining improvement.

These rehabilitation methods have been traditionally provided in two types of settings—inpatient and outpatient. At this writing, inpatient rehabilitation programs can be divided into three general categories (Hubbard et al., 1989, 1997):


Inpatient hospital-based treatment (now very rare)—from 7 to 11 days.


Nonhospital "residential rehabilitation"—from 30 to 90 days.


Therapeutic Communities—from 6 months to 2 years.

Outpatient forms of treatment (at least abstinence oriented treatments) range from 30 to 120 days (Hubbard et al., 1989, 1997). Many of the more intensive forms of outpatient treatment (Intensive Outpatient, Day-Hospital) begin with full or half-day sessions, five or more times per week for approximately one month. As the rehabilitation progresses the intensity of the treatment reduces to shorter duration sessions (one to two hours) delivered twice weekly to semi-monthly.

Regardless of whether the rehabilitation process is initiated in an inpatient or outpatient setting, most rehabilitation programs recognize the need for some level of continuing involvement with the rehabilitation process. Thus the final part of outpatient rehabilitation is typically called "Continuing Care" or "Aftercare" and includes weekly to monthly group support meetings continuing (in association with parallel activity in self-help groups) for as long as two years (McKay et al., 1998).

A Special Note on Maintenance Forms of Treatment. The opiate dependence treatment field has had the availability of orally administered, long-acting agonist medications. Three forms of opiate maintenance medications are currently available, Methadone, Levo-alpha-acetyl methadol (LAAM) and Buprenorphine. While each is different in nature and duration of action, they provide 24-72 hours of continuing relief from opiate withdrawal and craving; and serve as the basis for adjunctive social supportive therapy and medical care. This maintenance modality is quite similar in purpose and practice to the combined regimens of pharmacotherapy and supportive therapy now provided for depressed, diabetic, hypertensive, asthmatic, and other chronic illness patients. Like most forms of pharmacotherapy for patients with chronic illnesses, opiate maintenance treatments are designed with an indeterminate length—possibly continuing throughout the life of the patient.

Outcomes Expected from Addiction Rehabilitation Treatments—We have argued in earlier work (McLellan et al., 1996b, 1997a) that outcome expectations for substance abuse treatment should not be confined simply to reduction of alcohol and drug use since the public, the payers of treatment, and even the patients themselves are interested in a broader definition of "rehabilitation." Further, we have argued that for substance abuse treatments to be "worth it" to the multiple stakeholders who are involved in treatment, the positive effects of addiction treatment should be sustained beyond the end of the treatment period and carry on at least six to twelve months. Most researchers in the addiction field have taken a similar, broad view of outcome expectations in the addiction treatment field (See Anglin et al., 1989; Babor et al., 1988; Ball and Ross, 1991; De Leon, 1984; Hubbard et al., 1989, 1997; Simpson, 1981, 1997; Simpson et al., 1997a,b).

Thus in the review that follows we have given greater attention to studies where multiple outcomes were measured six to twelve months following inpatient discharge or at the same points during the course of the outpatient period of care. Further, we have considered three domains that we feel are relevant to the rehabilitative goals of the patient and to the public health and safety goals of those societal stakeholders that support treatment:


Sustained reduction of alcohol and drug use. This is the foremost goal of substance dependence treatments and we consider it as the primary outcome domain. Within the review, we accepted as operational evidence for improvement in this domain both objective data from urinalysis and breathalyzer readings as well as patients' self reports of alcohol and drug use when those reports were recorded by independent interviewers under conditions of privacy and impartiality.


Sustained increases in personal health and social function. Improvements in the medical/psychiatric health and social function of addicted patients are important from a societal perspective in that these improvements reduce the problems and expenses produced by the addiction. In addition, improvements in these areas are important for maintaining reductions in substance use. Within the review, we accepted evidence from measures such as general health status inventories, psychological symptom inventories, family function measures, and simple measures of days worked and dollars earned, collected either directly from the patient via confidential self report or from independent medical/psychiatric evaluations and employment records.


Sustained reductions in public health and public safety threats. The threats to public health and safety from substance abusing individuals come from behaviors that spread infectious diseases and from behaviors associated with personal and property crimes. With regard to infectious disease, the sharing of needles, unprotected sex, and trading sex for drugs are serious behaviors that have clearly been linked to addiction and are significant threats to public health. Within the review, we accepted evidence of improved public health from confidential self reporting techniques or (rarely) through laboratory tests. Public safety threats were measured in the studies reviewed either by confidential interviews and questionnaires or by objective records of arrests and incarcerations.

In our view, the first two domains are quite consistent with the "primary and secondary measures of effectiveness" typically used by the Food and Drug Administration to evaluate new drug or device applications in controlled clinical trials (FDA) and quite consistent with the mainstream of thought regarding the evaluation of other forms of health care (Stewart and Ware, 1989). The final outcome dimension we believe is more specific to the treatment of substance use disorders since it acknowledges the significant public health and public safety concerns associated with addiction.


Demographic Factors—While demographic factors are typically important predictors of the development of drug abuse problems (IOM, 1990b; Wilsnack and Wilsnack, 1993) there is little evidence that race, gender, age, or educational level are consistent predictors of treatment outcome—among those who begin a treatment episode. An inspection of a wide range of treatment outcome studies in the substance abuse rehabilitation field suggests that demographic factors such as age, education, race, and even treatment history are relatively poorly related to the three outcome domains defined above in any of the major rehabilitation modalities (see Ball and Ross, 1991; Finney and Moos, 1992; McLellan et al., 1994; Rounsaville et al., 1987). For example, a study of 649 patients entering 22 treatment programs (seven inpatient, eight outpatient, seven methadone maintenance) for treatment of primary alcohol, opiate, or cocaine dependence evaluated the contribution of demographic variables including age, ethnicity, gender, marital status, years of education, and years of problematic substance abuse (McLellan et al., 1994). Results showed that none of the demographic measures was a significant predictor of either posttreatment substance use or posttreatment social adjustment. Similarly, studies by Simpson and Savage (1980) showed no significant effect of demographic and social indicators in predicting multiple outcome domains among heroin addicts treated in methadone maintenance and outpatient drug free treatment.

Though less studied at this time, there may be some important exceptions to this conclusion. For example, pregnant and parenting women are an important subgroup of the larger patient population who require different features to permit access to treatment as well as different constellations of treatment to address their often significant treatment problems (see Gomberg and Nirenberg, 1993; Wilsnack and Wilsnack, 1993). There has been indication that these patients have been reluctant to get into "standard" treatments because of stigma and because of the absence of services for their children. There have been experimental programs created to meet the needs of this important subgroup—and some excellent evaluations have followed these groups posttreatment (see Hagan et al., 1994). There have been very few longer term outcome studies of specialized treatments for pregnant and parenting women and only the most obvious conclusions can be drawn regarding the factors that appear to be important for attraction, retention, and improved outcomes for these patients. These factors would include but not be restricted to:


The availability of care for children—and sometimes a residence that will accommodate the patients and their children. Many of the addicted women who could benefit from treatment are responsible for the care of children and facilities that will provide respite care are likely to be necessary for these women to be able to enter outpatient treatment. Other women will not have the resources to be self supporting and may need temporary accommodations for themselves and their children. Still others may require a facility that will offer protection from aggressive and/or drug involved partners. Problems of safety from physical and sexual abuse and separation from drug involved relationships are common in a large proportion of these women (Hagan et al., 1994; Wilsnack and Wilsnack, 1993; Schmidt and Weisner, 1995; Weisner and Schmidt, 1992). Residential settings are potentially important to address these problems.


The availability of general medical, OB/GYN, and psychiatric services. Disproportionately high numbers of these women have shown significant medical and psychiatric problems (Finnegan, 1991; Hagan et al., 1994; Schmidt and Weisner, 1995; Weisner and Schmidt, 1992; Wilsnack and Wilsnack, 1993). Therefore, it is important for programs that treat women substance abusers to provide adjunctive services in these areas.

Severity of Substance Use—Various measures of higher levels of severity and greater chronicity of patients' substance use patterns have been reliably associated with poorer retention in treatment and more rapid relapse to substance use following treatment. This has been true of both alcohol dependent patients (Babor et al., 1988; Finney and Moos, 1992); opiate dependent patients in therapeutic communities and in methadone maintenance (Ball and Ross, 1991; De Leon et al., 1984, 1994; Simpson, 1981, 1997a); and cocaine dependent patients treated in outpatient and inpatient settings (Alterman et al., 1994; Carroll et al., 1991; McLellan et al., 1994). The uniform nature of these predictive relationships across different types of drug dependence and treatment modalities suggests a pervasive trend toward poorer performance across all forms of treatment among those with longer durations and/or more intensive use patterns. This relationship is strongest between severity of substance use at treatment admission and posttreatment substance use. It is less clear whether the severity of alcohol and drug use at treatment admission is predictive of the other domains of personal health and social function, or public health and safety (McLellan et al., 1981b, 1992b, 1994). Thus, while the severity of substance use prior to treatment admission (measured in terms of amount, duration, and intensity of alcohol and drug use) is negatively related to posttreatment substance use—accounting for perhaps 10%-15% of outcome variance in that measure—it is less related to outcome in the other outcome domains (Babor et al., 1988; McLellan et al., 1994).

Severity of Psychiatric Problems—After the severity of the substance abuse problem, perhaps the most robust general patient variable predicting treatment response and posttreatment outcome has been the chronicity and severity of the psychiatric problems presented by the patient at the start of treatment (Carroll et al., 1993; Kadden et al., 1990; McLellan et al., 1983a,b, 1994; Powell et al., 1982; Project MATCH, 1997; Rounsaville et al., 1987; Woody et al., 1984, 1987). It is important to note that psychiatric problems have been measured using many scales and interviews in these studies, and all have attempted to distinguish more enduring or chronic psychiatric symptoms from the acute and temporary effects of alcohol and drug withdrawal. In the case of methadone maintained, opiate dependent patients, studies by McLellan and colleagues (1983a,b) indicated that the psychiatric severity scale from the Addiction Severity Index was the single best predictor of six month substance use, personal health, and social adjustment. Similar findings have been shown by Ball and Ross (1991) and by Kosten and colleagues (1987) and Rounsaville and colleagues (1983, 1987) with methadone maintained patients.

Measures of psychiatric severity have also been shown to be predictive of outcome in studies of opiate and multiple drug dependent patients entering an inpatient therapeutic community setting. For example, De Leon (1984) showed that opiate and non-opiate dependent patients with MMPI profiles indicative of high levels of psychopathology entering a therapeutic community were more likely to drop out of treatment and showed significantly less improvement on all outcome measures at discharge and at subsequent twelve month follow-up evaluations. In an earlier study of mixed opiate and non-opiate dependent male veterans entering into a therapeutic community McLellan and colleagues (1984) found that patients with the highest scores on the ASI psychiatric severity scale were most likely to drop out prematurely and actually showed 20%-40% less improvement than other patients who entered treatment at the same time. In that study, the "high psychiatric severity" patients who stayed in treatment longest actually showed the worst posttreatment status—suggesting that the therapeutic environment that had been demonstrably effective for patients with lower levels of psychiatric severity, was actually counter therapeutic for the high severity patients.

In the case of cocaine dependent patients, Carroll et al. (1991) also found poorer outcomes for patients with greater psychiatric pathology, as defined by scores on the Addiction Severity Index (ASI) psychiatric problem scale. Her findings were obtained in an outpatient rehabilitation setting. Similar results were found among cocaine dependent patients by Alterman et al. (1994) for patients treated in both a day-hospital and an inpatient rehabilitation setting.

Finally, there has been a great deal of evidence for the predictive power of general psychiatric symptomatology among alcohol dependent patients. Rounsaville and colleagues showed that psychiatric severity as measured by the ASI psychiatric scale was the best predictor of overall adjustment among previously treated alcohol dependent patients at a 2.5 year posttreatment follow-up (Rounsaville et al., 1987). Other authors have found that severity of depression (Powell et al., 1982; Schuckit et al., 1990) and anxiety (Brown et al., 1991; Schuckit et al., 1990) have been predictive of posttreatment drinking and posttreatment social adjustment among various samples of alcohol dependent patients. More recently, findings from the NIAAA sponsored, multisite study of patient treatment matching (Project MATCH, 1997) showed that the ASI psychiatric scale was a significant general predictor of posttreatment drinking and posttreatment social adjustment in a sample of more than 1200 alcohol dependent patients in three types of outpatient treatment.

Note: While there are a number of studies relating severity of psychopathology to posttreatment outcome, it should be noted that Schuckit and his colleagues have argued cogently against "over diagnosing" psychiatric symptoms, especially among alcohol dependent patients (Brown et al., 1991; Schuckit and Monteiro, 1988). These authors have shown that much of the serious psychopathology seen among alcohol dependent patients at treatment admission is reduced following even four weeks of abstinence. There is also evidence for rapid dissipation of psychiatric symptoms following abstinence from cocaine (Satel et al., 1991; Weddington, 1992). This proviso suggests that care should be taken to distinguish acute alcohol and/or drug related psychopathology from more enduring and chronic psychiatric symptoms.

Patient Motivation and Stage of Change—Evidence for patient "motivation for treatment" has traditionally been measured as the extent to which patients have freely entered into treatment. Conversely, patients who have been coerced into treatment based on pressure from legal, family, or employment sources, have been considered "treatment resistant." While this is a face valid measure of motivation—and presumably a good predictor of patient performance during and following treatment—the large literature on coerced treatment indicates the opposite of what would be expected. That is, patients who have been forced to enter a substance abuse treatment have shown during and posttreatment results that are quite similar to those shown by supposedly "internally motivated" patients (Inciardi, 1988; Lawental et al., 1996; Roman, 1988). This rather broad literature has led to the conclusion that when "motivation" is conceptualized and measured in terms of the degree to which the patient has been coerced into treatment, it is not an important predictor of treatment response.

However, there is rapidly growing body of research indicating that when motivation is defined as "readiness for change" and is conceptualized and measured in stages as suggested by Prochaska, DiClemente and their associates (e.g., Prochaska and DiClemente, 1984; Prochaska et al., 1992), "stage of change" motivation can be a very important predictor of treatment response and treatment outcome. According to the stage of change model, the process of behavior change occurs in a progression of five distinct stages, each characterized by a different constellation of attitudes and behaviors. An individual in the "precontemplation stage" has no awareness of a problem and no desire to change. A patient in the "preparation stage" has made the decision to change and is already taking steps to do so. A patient in the "maintenance stage" has shown change and is maintaining the changed behavior (see Prochaska and DiClemente, 1984).

The power of the model comes from two sets of findings. First, a relatively simple measure of stage of change such as the University of Rhode Island Change Assessment (URICA) (Prochaska and DiClemente, 1984; Prochaska et al., 1992) can apparently identify individuals in the precontemplation stage of change for whom traditional forms of rehabilitation treatment (most of which assume desire and ability to change as a precondition of admission) will not be effective. Specifically, there are several studies showing failure of traditional forms of counseling and therapy in patients identified as "precontemplators" on the URICA (DiClemente et al., 1991; Heather et al., 1993; Marlatt, 1988). The second important finding from work with this measure is that the "stage of change" is apparently an important predictor of treatment response and treatment outcome across all types of substance dependent patient samples (especially alcohol and nicotine dependent patients, but it is less studied among cocaine and opiate dependent patients), even those who are not in treatment (DiClemente et al., 1991).

The model provides a way of identifying patients with different levels of motivation and outlines a way of tailoring interventions to match their stage of change. It makes sense that those patients who consciously intend to change are more likely to succeed in treatment than those who do not. In this regard, the majority of the predictive power of the stage of change model has been the identification of precontemplators. Additional research is warranted to determine the extent to which the remaining stages of change can predict response to standard rehabilitation treatments.

Employment—There is ample indication from research with methadone maintained patients that employment, employability, and self support skills are a significant problem for this population; and that unemployed patients are more likely to drop out of treatment prematurely and to relapse to substance use early following treatment (Dennis et al., 1993; Hubbard et al., 1989; Platt, 1995). This was illustrated in a study of male veterans in methadone maintenance treatment by McLellan and colleagues (1981a). These authors found that patients who derived most of their income from employment showed more improvement and better six-month outcomes in several outcome domains including drug use, legal, and psychiatric problems and of course employment, than similar patients who derived the majority of their income from unemployment or welfare.

Hubbard and his colleagues (1989) showed that the development of employable skills and the capacity for self support were among the most important requirements for sustained reductions in drug use among a large cohort of drug dependent patients in treatment. Similar findings were shown by De Leon among opiate dependent patients in a therapeutic community setting (1984). Finally, Hall and her colleagues showed that unemployment was a significant predictor of early relapse to opiate use among detoxified heroin dependent males (1981). Similarly, in a sample of primarily employed, multiple substance abusers entering private inpatient or outpatient, abstinence oriented treatment programs, McLellan and colleagues showed that employment problems (getting along with supervisor, dissatisfaction with present job and salary, etc.) were one of the most significant predictors of both posttreatment substance use as well as posttreatment personal health and social function, measured at six-month follow-up (McLellan et al., 1994).

Family and Social Supports—Social supports have been widely studied in the field of alcohol and drug dependence. Social support has been conceptualized variously as the active participation in peer-supported treatments such as AA/NA; as the availability of relationships that are not conflict producing (McLellan et al., 1980, 1984) and in more detailed models, as the level of support for abstinence from those relationships (Longabough et al., 1993, 1995). Among alcohol dependent patients, there is often indication of significant ''dysfunction" among the families, and in turn, the level of this disruption has been associated with earlier drop out from outpatient treatment (McLellan et al., 1983a, 1994), earlier relapse to drinking following treatment (Moos and Moos, 1984) and generally worse posttreatment function (McKay et al., 1994; McCrady et al., 1986; Moos and Moos, 1984).

Among opiate dependent patients there has been very little work associated with family and social supports as they relate to outcome. One prominent exception has been the work of Stanton and colleagues who showed both significant disruption and social pathology among families of methadone maintained patients; and a significant relationship between level of social pathology in the family of origin (typically also the posttreatment family environment in these patients) and use of heroin during methadone treatment (Stanton 1979; Stanton and Todd, 1982). McLellan et al. (1983a,b) found that the family relationship scale on the ASI was one of three significant predictors of posttreatment drug use and general personal and social function among opiate dependent patients in either inpatient therapeutic community or outpatient methadone maintenance treatment. In a subsequent study, this group also found that the family relationship scale was a significant predictor of posttreatment social function and relapse to cocaine and alcohol use among insured, working patients referred to substance abuse treatment through their employee assistance program (McLellan et al., 1993a, 1997a). An interesting, paradoxical finding in this area was reported by Havassy and her colleagues (1991). Among primarily African-American cocaine dependent patients, these authors found a paradoxically negative relationship between the reported number of available family and friends of the patient and relapse to cocaine use following treatment: the more friends and family available to the patient, the earlier the return to cocaine use. The authors' hypothesize that in this severely affected cohort of patients, the only available sources of social support may have been associates with whom the patients had previously used drugs.


Patient factors have been much more widely studied than treatment setting, modality, process, and service factors as predictors of outcome from addiction rehabilitation treatments. Perhaps the major reason for this is that while there have been many reliable and valid measures of various patient characteristics, there are still very few measures of treatment setting (Moos, 1974; Moos et al., 1990) or treatment services (McLellan et al., 1992a; Widman et al., 1997).

There is good news however, regarding the study of treatment factors in the substance abuse field. Recent developments in the psychotherapy field have led to the creation of manual-based treatments and with them, appropriate measures of treatment fidelity and integrity. Following on this progress, the multisite NIAAA study of patient treatment matching (Project MATCH, 1997) has provided the field with new manuals for the three Project MATCH treatments as well as additional measures of the nature and fidelity of each treatment. These are likely to improve the study of addiction treatment process in the years to come. Below we review several dimensions or characteristics of treatment that have been studied and that have shown some relationship with outcome following treatment.

Setting of Treatment—There have now been many studies investigating potential differences in outcome between various forms of inpatient and outpatient rehabilitation. For example, studies by McCrady et al. (1986) and Alterman et al. (1994) randomly assigned alcohol dependent patients to an equal length (28-30 days) of either inpatient or day-hospital rehabilitation, where the treatment elements were also designed to be similar. Both studies showed very similar findings. Patients in both the inpatient and outpatient arms of both these studies showed substantial and significant reductions in alcohol use, as well as improvements in many other areas of personal health and social function—suggesting that both settings of care were able to produce substantial benefits. At the same time, a wide range of outcome measures collected at six-month follow-up in both studies, showed essentially no statistically significant or clinically important differences between the two settings of care—suggesting that the setting of care might not be an important contributor to outcome. A further analysis of data from the Alterman et al. study (McKay et al., 1995) indicated that 12-month outcomes in the day hospital group were generally at least equal to outcomes following inpatient care, and pertained to both randomized and nonrandomized subjects.

Consistent with the results of these two studies, reviews of the literature on inpatient and outpatient alcohol rehabilitation by Miller and Hester (1986) and Holder et al. (1991) also concluded that across a range of study designs and patient populations there was no significant advantage provided by inpatient care over outpatient care in the rehabilitation of alcohol dependence, despite the substantial difference in costs. In contrast, a widely cited study by Walsh et al. (1991) did find a significant difference in outcome favoring an inpatient program. However, this difference was shown among employed alcohol dependent patients who were assigned to either an inpatient program plus Alcoholics Anonymous (AA) or to AA meetings only (rather than to formal outpatient treatment). One recent review of the alcohol inpatient-outpatient literature did conclude that in studies that found an advantage to inpatient care over outpatient treatment, outpatients did not receive inpatient detoxification and the studies tended to not have social stability inclusion criteria or to require randomization (Finney et al., 1996). This review points to the need to consider "real world" factors when evaluating the effectiveness of different treatment settings.

In the field of cocaine dependence treatment, there have also been several studies examining the role of treatment setting. Again, while there is evidence for high attrition rates (e.g., Kang et al., 1991), there is still evidence indicting that outpatient treatments for cocaine dependence can be effective, even for patients with relatively limited social resources. In a recent study, Alterman and his colleagues followed up a prior comparison study of inpatient and day-hospital treatment of alcohol dependence (1994) with an identical examination comparing the effectiveness of four weeks of intensive, highly structured day hospital treatment (27 hours weekly) with that of inpatient treatment (48 hours weekly) for cocaine dependence. The subjects were primarily inner city, male African Americans treated at a Veterans Administration Medical Center. The inpatient treatment completion rate of 89% was significantly higher than the day-hospital completion rate of 54% . However, at seven months posttreatment entry self reported outcomes indicated considerable improvements for both groups in drug and alcohol use, family/social, legal, employment, and psychiatric problems. The finding of reduced self reported cocaine use was supported by urine screening results. Both self report and urine data indicated 50%-60% abstinence for both groups at the follow-up assessment. The comparability of both treatment settings was also evident in 12-month outcomes in both randomized and self-selecting patients (McKay et al., 1994).

Similar findings have been shown in field studies of private substance abuse treatment programs treating primarily cocaine and cocaine-plus-alcohol-dependent patients (McLellan et al., 1993a; Pettinati et al., 1998). In all of these studies, patients who were assigned to one of several outpatient treatment programs, were less likely to complete treatment than those assigned to the inpatient programs; but those who did complete treatment showed equal levels of improvement and outcome in the inpatient and outpatient settings. It is important to note that virtually all studies of this type have shown greater engagement and retention of patients in inpatient settings.

There have been at least two attempts to formalize clinical decision processes regarding who should, and should not be assigned to inpatient and outpatient settings of care (Cleveland Criteria; American Society of Addiction Medicine [ASAM] Criteria). McKay et al. (1992) failed to show evidence for the predictive validity of the Cleveland placement criteria at least when applied to the assignment of alcohol and drug dependent patients to day hospital or inpatient care. That is, patients who met the Cleveland Criteria for inpatient treatment did not have worse outcomes than those who met criteria for day hospital only when both groups received day hospital treatment. If the Cleveland Criteria had been valid, those who "needed inpatient treatment" but did not receive it should have had poorer outcomes than those who were appropriately "matched" to day hospital. In a similar study evaluating the psychosocial predictors from the ASAM criteria, McKay et al. (1997b) did find at least partial support for the predictive validity of these placement variables. That is, among patients who "needed inpatient treatment" as defined by the psychosocial elements of the ASAM criteria, those who were randomly assigned to outpatient care did show somewhat worse abstinence rates and generally poorer social outcomes than those who were randomly assigned to inpatient rehabilitation. The retrospective nature of this study made it impossible to complete a full evaluation of these criteria.

The most recent versions of the ASAM criteria have attempted to make very fine grained decisions regarding placements to levels of care defined by the amount and quality of medical supervision and monitoring. Research is needed to determine the predictive validity of these finer distinctions and whether placements to settings and modalities with "more medical supervision" actually receive more medical contact or services than placements that are not expected to receive such services.

Length of Treatment/Compliance with Treatment—Perhaps the most robust and pervasive indicator of favorable posttreatment outcome in all forms of substance abuse rehabilitation has been length of stay in treatment. Virtually all studies of rehabilitation have shown that patients who stay in treatment longer and/or attend more treatment sessions, have better posttreatment outcomes (Ball and Ross, 1991; De Leon, 1984, 1994; Hubbard et al., 1997; Simpson 1981, 1997; Simpson et al., 1997a,b). Specifically, several studies have suggested that outpatient treatments of less than 90 days are more likely to result in early return to drug use and generally poorer response than treatments of longer duration (Ball and Ross, 1991; Simpson, 1981, 1997; Simpson et al., 1997a,b).

Though length of stay is a very robust, positive predictor of treatment outcome, the nature of this relationship is still ambiguous. Clearly, one possibility is that patients who enter treatment gradually acquire new motivation, skills, attitudes, knowledge, and supports over the course of their stay in treatment; that those who stay longer acquire more of these favorable attributes and qualities; and that the gradual acquisition of these qualities or services is the reason for the favorable outcomes. An equally plausible possibility is that "better motivated and better adjusted patients" come into treatment ready and able to change; that the decisions they made to "change their lives" were made in advance of their admission and because of this greater motivation and "treatment readiness" they are likely to stay longer in treatment and to do more of what is recommended. These two interpretations of the same facts have very different implications for treatment practice. If treatment gradually produces positive changes over time, it is obviously clinically sound practice to retain patients longer—perhaps even through coercion—and to provide them with more services during treatment. On the other hand, if well motivated, high functioning, compliant patients enter treatment with the requisite skills and supports necessary to do well, then efforts to provide more services or to coerce patients into longer stays may not add to the effectiveness of more streamlined and less expensive rehabilitation efforts.

Participation in AA/NA—AA is of course recognized as a self-help or mutual support organization and not a formal treatment. For this reason, and because of the anonymous quality of the group, not much research has been done to evaluate this important part of substance abuse rehabilitation until recently (McLatchie and Lomp, 1988; McCrady and Miller, 1993; Nowinsky and Baker, 1992; Project MATCH, 1997). While there has always been consensual validation for the value of AA and other peer support forms of treatment, the past few years have witnessed new evidence showing that patients who have an AA sponsor, or who have participated in the fellowship activities—have much better abstinence records than patients who have received rehabilitation treatments but have not continued in AA. McKay and his colleagues (1997a) found that participation in posttreatment self-help groups predicted better outcome among a group of cocaine or alcohol dependent veterans in a day hospital rehabilitation program. Timko et al., (1994) found that more AA attendance was associated with better 1-year outcomes among previously untreated problem drinkers regardless of whether they received inpatient, outpatient, or no other treatment. Finally, a recent review of the literature on the impact of self-help programs concluded that greater participation was generally associated with better alcohol and psychosocial outcomes, although the magnitude of the effects tended to vary as a function of the quality of the study and whether patients were treated in inpatient or outpatient settings (Tonigan et al., 1996).

There has been less research in the use of self-help organizations among cocaine and/or opiate dependent patients. However, a recent study of cocaine patients participating in outpatient counseling and psychotherapy showed that while only 34% attended a cocaine anonymous (CA) meeting, 55% of those who did became abstinent as compared with only 38% of those who did not attend CA.

In contemporary addiction treatment, AA has become synonymous with the last part of rehabilitation—aftercare. Virtually all alcohol dependence rehabilitation programs and most cocaine dependence rehabilitation programs refer patients to AA programs with instructions to get a sponsor, "share and chair" at meetings, and to attend 90 meetings in 90 days as a continued commitment to sobriety. Thus, while the research studies done to date have generally suggested that the peer support component of rehabilitation is valuable, it is also difficult to sort out the extent to which AA attendance constitutes an active ingredient of successful treatment and/or the extent to which it is simply a marker of general treatment compliance and commitment to abstinence.

In this regard, several investigators have studied the relationship of completing various 12-step processes during the course of rehabilitation, to relapse following treatment. Morgenstern and colleagues reported that patients who adopted more of the attitudinal and behavioral tenets of the 12-step model of rehabilitation such as admission of powerlessness, acceptance of a higher power, commitment to AA, and agreement that alcoholism is a disease, were no more (or less) likely to relapse following treatment than patients who had adopted very few of the 12-step tenets by the end of the rehabilitation treatment (Morgenstern et al., 1997). At the same time, two general tenets found in all rehabilitation models—greater commitment to abstinence and greater intention to avoid high risk situations—did predict a lower likelihood of relapse (Morgenstern et al., 1997). In another analysis from the same study, greater affiliation with AA following treatment predicted better outcomes. AA affiliation was in turn positively associated with self-efficacy, motivation, and coping efforts, which were themselves significant predictors of outcome (Morgenstern et al., 1997). Thus, more research in this area is warranted to determine how participation in AA exerts its positive effects.

The Therapist or Counselor—There is a growing body of research suggesting that having access to regular drug/alcohol counseling can make an important contribution to the engagement and participation of the patient in treatment and to the posttreatment outcome. Perhaps the clearest example of the role of the counselor and at least individual counseling was shown in a study of methadone maintained patients, all within the same treatment program and all receiving the same methadone dose, who were randomly assigned to receive counseling or no counseling in addition to the methadone (McLellan et al., 1993b). Results were unequivocal showing that 68% of patients assigned to the no counseling condition failed to reduce drug use (confirmed by urinalysis) and 34% of these patients required at least one episode of emergency medical care. In contrast, no patient in the counseling groups required emergency medical care, 63% showed sustained elimination of opiate use, and 41% showed sustained elimination of cocaine use over the six months of the trial.

A study by Fiorentine and Anglin (1997) as part of a larger "Target Cities" evaluation also showed the contribution of counseling in drug rehabilitation. Group counseling was the most common modality (averaging 9.5 sessions per month) followed by 12-step meetings (average 7.5 times per month) and individual counseling (average 4.7 times per month). Greater frequency of both group and individual counseling sessions were shown to decrease the likelihood of relapse over the subsequent six months. One important contribution of this study, given the above cautions regarding the role of simple length of stay in determining treatment outcome (see above), is that the relationships shown between more counseling and lower likelihood of relapse to cocaine use were seen even among patients who completed treatment—that is, having approximately the same tenure in the programs. Thus, it may be that beyond the simple effects of attending a program, more involvement with the counseling activities is important for improved outcome.

At least four studies of substance abuse treatment have documented between-therapist differences in patient outcomes. These differences have emerged both among professional psychotherapists with doctoral level training and among paraprofessional counselors. Luborsky et al. (1985) found outcome differences in a variety of areas among nine professional therapists providing ancillary psychotherapy to methadone maintenance patients. McLellan et al. (1988) found that assignment to one of five methadone maintenance counselors resulted in significant differences in treatment progress over the following six months. Specifically, patients transferred to one counselor achieved significant reductions in illicit drug use, unemployment, and arrests while concurrently reducing their average methadone dose. In contrast, patients transferred to another counselor evidenced increased unemployment and illicit drug use while their average methadone dose went up. In a study of two different interventions for problem drinkers, Miller, Taylor, and West (1980) found significant differences between paraprofessional therapists in the percentage of their patients who improved by six-month follow-up. These percentages varied from 25 % for the least effective therapist to 100% for the most effective therapist. Finally, McCaul and Svikis (1991) reported significant differences in posttreatment drinking rates and several other outcomes among alcohol dependent patients assigned to different individual counselors within an alcohol treatment program.

There is much research that needs to be done in this area. Although it is relatively clear that therapists and counselors differ considerably in the extent to which they are able to help their patients achieve positive outcomes, it is less clear what distinguishes more effective from less effective therapists. In an experimental study of two different therapist styles, Miller, Benefield, and Tonigan (1993) found that a client centered approach emphasizing reflective listening was more effective for problem drinkers than a directive, confrontational approach. In a review of the literature on therapist differences in substance abuse treatment, Najavits and Weiss (1994) concluded, "The only consistent finding has been that therapists' in-session interpersonal functioning is positively associated with greater effectiveness" (p. 683). Among indicators of interpersonal functioning were the ability to form a helping alliance (Luborsky et al., 1985), measures of the level of accurate empathy (Miller et al., 1980; Valle, 1981), and a measure of "genuineness," "concreteness," and "respect" (Valle, 1981).

It should be noted that there are a variety of certification programs for counselors (Committee on Addiction Rehabilitation [CARF] and Certified Addictions Counselor [CAC]) as well as other professions treating substance dependent patients (American Society of Addiction Medicine; American Academy of Psychiatrists in Addiction; recent added certification for psychologists through the American Psychological Association). These "added qualification certificates" are offered throughout the country, usually by professional organizations. Although the efforts of these professional organizations to bring needed training and proficiency to the treatment of addicted persons are commendable, we were unable to find any studies validating whether patients treated by "certified" addictions counselors, physicians, or psychologists have better outcomes than patients treated by noncertified individuals. This is an important gap in the existing literature and results from such studies would be quite important for the licensing efforts and health policy decisions of many states and health care organizations.

Medications—At this writing, there is a great deal of research sponsored by both the National Institute on Alcoholism and Alcohol Abuse and the National Institute on Drug Abuse aimed at developing useful medications for the treatment of substance dependent persons. Great progress has been made over the past ten years in the development of new medications and in the application of existing medications for the treatment of particular conditions associated with substance dependence and for particular types of substance dependent patients (see IOM, 1995; O'Brien, 1996; O'Brien and McKay, in press). Here we have only summarized some of the clearest results from the use of agonist and antagonist medications in the treatment of substance dependence and have provided citations for more comprehensive medication reviews for interested readers.

Agonist Medications—Methadone has been an approved agonist medication for the maintenance treatment of opiate dependence for more than 25 years. The long-acting form of methadone (48- to 72-hour duration), LAAM has recently received FDA approval and has been accepted by 16 states for prescription only at methadone maintenance programs. Buprenorphine is a partial opiate agonist that has been widely used in Europe and in the United States. It is thought to have some advantages over methadone in that it produces far fewer (often none) withdrawal symptoms (see Bickel et al., 1997). At this writing, it is not yet approved for use.

Among the most robust findings in the treatment literature is the relationship between dose of methadone and general outcome in methadone treatment (Ball and Ross, 1991; D'Aunno and Vaughn, 1992, 1995; Institute of Medicine, 1995). Higher doses are more effective than lower doses. In a well controlled double blind multisite VA study, Ling et al. (1976) found that 100 mg per day was superior to 50 mg as indicated by staff ratings of global improvement and by a drug use index comprised of weighted results of opiate urine tests. In a more recent randomized, double-blind study, Strain et al. (1993) compared 50 mg and 20 mg with a 0 mg placebo-only group. They found orderly dose-response effects on treatment retention, and they found that 50 mg was more effective than 20 mg or 0 mg at decreasing opiate and cocaine use as measured by urinalysis results. In a randomized double blind comparison of moderate (40-50 mg) and high (80-100 mg) dose methadone, Strain and his colleagues (1996) found a significantly lower rate of opiate positive urine specimens among patients receiving the high dose of methadone (53% vs. 62%). There are many other studies of opiate agonist medications, but space limitations do not permit more detail here (see IOM, 1995 for additional information).

Antagonist and Blocking Agents—Naltrexone has been used for more than 20 years in the treatment of opiate dependence (see Greenstein et al., 1981; O'Brien et al., 1984). It is an orally administered opiate antagonist that blocks actions of externally administered opiates such as heroin by competitive binding to opiate receptors. It has been particularly effective as an adjunct to probation in opiate addicted federal probationers (see Cornish et al., 1997). More recently, naltrexone (marketed under the trade name Revia®) has been found to be effective in the treatment of alcohol dependence (O'Malley et al., 1992; Volpicelli et al., 1992). Naltrexone at 50mg/day has been approved by the FDA for use with alcohol dependent patients since independent studies have shown it to be a safe, effective pharmacological adjunct for reducing heavy alcohol use among alcohol dependent patients. Its mechanism of action appears to be the blocking of at least some of the "high" produced by alcohol consumption, again through competitive binding with the mu opiate receptors (O'Malley et al., 1992; Volpicelli et al., 1992).

With regard to other medications designed to block the effects of an abused drug, disulfiram (Antabuse ®) has been used the longest and most pervasively in the treatment of alcohol dependence (see Fuller et al., 1986). However, disulfiram seems to be most effective under certain conditions, such as when the patient contracts to having a significant other witness him or her take the medication each day. More recently, European researchers have found encouraging results with acamprosate as a treatment for alcoholism (Ladewig et al., 1993; Lhuintre et al., 1990). While acamprosate acts on different receptor systems than naltrexone, the clinical results are remarkably similar (Anton, 1995; Ladewig et al., 1993; Lhuintre et al., 1990). Alcohol dependent patients who take acamprosate have shown 30% greater posttreatment abstinence rates at six-month follow-up than those randomly assigned to placebo. Further, those who have returned to drinking while taking acamprosate report less heavy drinking (greater than five drinks per day) than those who returned to drinking while prescribed placebo (Anton, 1995). While both of these medications can be used for extended periods, in practice they are generally prescribed for about one to three months as part of a more general rehabilitation program that includes behavioral change strategies (see review by Anton, 1995).

There have been many agents tried as blocking agents in the treatment of cocaine dependence and while this literature is quite large, it has been disappointing (see Institute of Medicine, 1995; O'Brien, 1996; O'Brien and McKay, in press). At this writing, there is no convincing evidence that any of the various types of cocaine blocking agents are truly effective for even brief periods of time or for even a significant minority of affected patients. Research continues in this important area and there have been indications of a potentially successful "vaccine" that may be able to immediately metabolize and inactivate active metabolites of cocaine (see Fox, 1997). This promising work is currently being tested in animal models, but there are no treatment relevant medications available for cocaine rehabilitation at this time.

Although the use of opiate and alcohol antagonists or blocking agents is increasing as addiction physicians are more comfortable with the prescription of adjunctive medications and as more substance dependence is treated by primary care physicians in office settings (see Fleming and Barry, 1992), there are still relatively few patients that receive—or practitioners that prescribe—these medications (Institute of Medicine, 1995). Furthermore, the available literature in this area still does not provide an unambiguous conclusion regarding the parameters that are most effective when using antagonist or ''blocking" pharmacotherapy. For example, a recent cautionary article by Moitto and colleagues warned about an unusually high rate of deaths (particularly suicides) among opiate dependent individuals who were transferred to naltrexone (Moitto et al., 1997). The appropriate use of these antagonist or blocking medications in "real world" treatment of substance dependence disorders may be among the most important topics for future research in the treatment field. These medications are often expensive and managed care companies have been slow to permit these medications to reach formularies (see Institute of Medicine, 1995; O'Brien, 1996; O'Brien and McKay, in press). In addition, there is a need for long-term studies of patients who have been prescribed these medications as well as studies examining the most appropriate and efficient mix of psychosocial and pharmacological services to maximize rehabilitation for various types of substance dependent patients.

Provision of Specialized Services—The majority of patients admitted to substance abuse treatment have significant "addiction related" problems in one or more areas such as medical status, employment, family relations, and/or psychiatric function (McLellan and Weisner, 1996). As has been indicated above, the severity of these problems at the time of treatment admission is generally a good negative predictor of posttreatment outcome. Studies have documented that strategies designed to direct and focus specialized services to these "addiction related" problems can be applied in standard clinical settings and can be effective in improving the results of substance abuse treatment. Again, this conclusion follows more than a decade of research showing that the addition of professional marital counseling (Fals-Stewart et al., 1996; McCrady et al., 1986; O'Farrell et al., in press; Stanton and Todd, 1982), psychotherapy (Carroll et al., 1991, 1993, 1994a,b; Woody et al., 1983, 1984, 1987, 1995) and medical care (Fleming and Barry, 1992) produces clinically and significantly better outcomes from substance abuse treatment.

It should be noted that in some cases, these adjunctive forms of therapy and services have been most clearly associated with improved personal health and social function following treatment but not as well related to reduced alcohol and drug use. In addition, and not surprisingly, these treatments have only been shown to be effective with those patients having more severe problems in the target area (matching effect)—that is, if there has been no indication of a relatively severe problem in the target area, there has typically been no evidence that the provision of the target therapy is effective or worthwhile (see Woody et al., 1984). One exception to this appears to be behavioral marital or couples therapy, which has typically demonstrated a "main effect" for all couples in the studies. This might be because most marriages in which one or both partners are actively abusing alcohol or drugs could be characterized by fairly severe marital problems. However, even in the case of marital therapy, some matching effects have been found. One study found that the effectiveness of couples therapy for alcoholics varied as a function of complex interactions involving the patient's degree of investment in relationships, degree of support for abstinence from significant others, and planned number of conjoint sessions (Longabaugh et al., 1995).

Community Reinforcement and Contingency Contracting—Azrin and colleagues initially developed the "Community Reinforcement Approach" (CRA) and tested it against other "standard" treatment interventions (Azrin et al., 1982). CRA includes conjoint therapy, job finding training, counseling focused on alcohol-free social and recreational activities, monitored disulfiram, and an alcohol-free social club. The goal of CRA is to make abstinence more rewarding than continued use (Meyers and Smith, 1995). In a study in which patients were randomly assigned to CRA or to a standard hospital treatment program, those getting CRA drank less, spent fewer days away from home, worked more days, and were institutionalized less over a 24-month follow-up (Azrin et al., 1982).

A more recent set of studies by Higgins et al. (Higgins et al., 1991, 1993, 1994, 1995) has used the CRA approach with cocaine dependent patients. Here, cocaine dependent patients seeking outpatient treatment were randomly assigned to receive either standard drug counseling and referral to AA, or a multicomponent behavioral treatment integrating contingency managed counseling, community-based incentives, and family therapy comparable to the CRA model (Higgins et al., 1991). The CRA model retained more patients in treatment, produced more abstinent patients and longer periods of abstinence, and produced greater improvements in personal function than the standard counseling approach. Following the overall findings, this group of investigators systematically "disassembled" the CRA model and examined the individual "ingredients" of family therapy (Higgins et al., 1993), incentives (Higgins et al., 1994), and the contingency based counseling (Higgins et al., 1995) as compared against groups who received comparable amounts of all components except the target ingredient. In each case, these systematic and controlled examinations indicated that these individual components made a significant contribution to the outcomes observed, thus proving their added value in the rehabilitation effort. Extending this work on the use of positive reinforcement and behavioral contracting, Silverman and colleagues (Silverman et al., 1996) used essentially the same reinforcement contingencies and contracting procedures that had been applied by Azrin and Higgins to improve the performance of methadone maintained patients.

"Matching" Patients and Treatments—The past two decades have witnessed a great number of research studies attempting to "match" patients with specific types, modalities or settings of treatment. The approach to patient-treatment "matching" that has received the greatest attention from substance abuse treatment researchers involves attempting to identify the characteristics of individual patients that predict the best response to different forms of addiction treatments (e.g., cognitive-behavioral vs. 12-Step, or inpatient vs. outpatient) (Mattson et al., 1994; Project MATCH Research Group, 1997). In general, the majority of these "patient-to-treatment" matching studies have not shown robust or generalizable findings (see Gastfriend and McLellan, 1997). Another approach to matching has been to assess patients' problem severity in a range of areas at intake and then ''match" the specific and necessary services to the particular problems presented at the assessment. This has been called "problem-to-service" matching (McLellan et al., 1997b). This approach may have more practical application as it is consonant with the "individually tailored treatment" philosophy that has been espoused by most practitioners.

Substance abusers with comorbid psychiatric problems may be particularly good candidates for the "problem-to-service" matching approach; especially the addition of specialized psychiatric services for those most severely affected by psychiatric problems. For example, recent studies suggest that tricyclic antidepressants and the selective serotonergic medication fluoxetine may reduce both drinking and depression levels in alcoholics with major depression (Cornelius et al., 1997; Mason et al., 1996; McGrath et al., 1996). Similarly, the anxiolytic buspirone may reduce drinking in alcoholics with a comorbid anxiety disorder (Kranzler et al., 1994). Highly structured relapse prevention interventions may also be more effective in decreasing cocaine use, as compared to less structured interventions, in cocaine abusers with comorbid depression (Carroll et al., 1995).

Woody and colleagues have evaluated the value of individual psychotherapy when added to paraprofessional counseling services in the course of methadone maintenance treatment (Woody et al., 1983). In that study patients were randomly assigned to receive standard drug counseling alone (DC group) or drug counseling plus one of two forms of professional therapy: supportive-expressive psychotherapy (SE) or cognitive-behavioral psychotherapy (CB) over a six month period. Results showed that patients receiving psychotherapy showed greater reductions in drug use, more improvements in health and personal function, and greater reductions in crime than those receiving counseling alone. Stratification of patients according to their levels of psychiatric symptoms at intake showed that the main psychotherapy effect was seen in those with greater than average levels of psychiatric symptoms. Specifically, patients with low symptom levels made considerable gains with counseling alone and there were no differences between types of treatment. However, patients with more severe psychiatric problems showed few gains with counseling alone but substantial improvements with the addition of the professional psychotherapy.

Another type of substance abuser that can pose particular problems for outpatient treatment is the cocaine dependent patient who is unable to achieve remission from cocaine dependence early in outpatient treatment. Several randomized studies suggest that highly structured cognitive-behavioral treatment is particularly efficacious with such individuals. In two outpatient studies with cocaine abusers, those with more severe cocaine problems at intake had significantly better cocaine use outcomes if they received structured relapse prevention rather than interpersonal or clinical management treatments (Carroll et al., 1991, 1994b). In a third study, cocaine dependent patients who continued to use cocaine during a four-week intensive outpatient treatment program (IOP) had much better cocaine use outcomes if they subsequently received aftercare that included a combination of group therapy and a structured relapse prevention protocol delivered through individual sessions rather than aftercare that consisted of group therapy alone (McKay et al., 1998).

The impact of adding additional, professionally delivered treatment services to a basic methadone program was investigated by McLellan and colleagues (McLellan et al., 1993b). In this study, patients were randomly assigned to receive (a) methadone only; (b) methadone plus standard counseling; or (c) methadone and counseling plus on-site medical, psychiatric, employment, and family therapy services (the "enhanced" condition). Although these additional services were not "matched" to patients on an individual basis, most of the patients in the study were polydrug abusers with relatively high problem levels in other areas. On most outcome measures, the best results were obtained in the enhanced condition, followed by methadone plus counseling, and methadone alone. Improvements in the enhanced condition were significantly better than those in the methadone plus counseling condition in the areas of employment, alcohol use, criminal activity, and psychiatric status. These results demonstrate the value of providing additional professional treatment services to polyproblem substance abusers, even when these services are not "matched" to specific problems at the level of the individual patient.

McLellan and colleagues recently attempted a different type of "problems to services" matching research in two inpatient and two outpatient private treatment programs (McLellan et al., 1997b). Patients in the study (N = 130) were assessed with the ASI at intake and placed in a program that was acceptable to both the Employee Assistance Program referral source and the patient. At intake, patients were also randomized to either the standard or "matched" services conditions. In the standard condition, the treatment program received information from the intake ASI, and personnel were instructed to treat the patient in the "standard manner, as though there were no evaluation study ongoing." The programs were instructed to not withhold any services from patients in the standard condition. Patients who were randomly assigned to the matched services condition were also placed in one of the four treatment programs and ASI information was forwarded to that program. However, the programs agreed to provide at least three individual sessions in the areas of employment, family/social relations, or psychiatric health delivered by a professionally trained staff person to improve functioning in those areas when a patient evidenced a significant degree of impairment in one or more of these areas at intake. For example, a patient whose intake ASI revealed significant impairments in the areas of social and psychiatric functioning would receive at least six individual sessions, three by a psychiatrist and three by a social worker.

The standard and matched patients were compared on a number of measures, including number of services received while in treatment, treatment completion rates, intake to six-month improvements in the seven problem areas assessed by the ASI, and other key outcomes at six months. Matched patients received significantly more psychiatric and employment services than standard patients, but not more family/social services or alcohol and drug services. Second, matched patients were more likely to complete treatment (93% vs. 81%), and showed more improvement in the areas of employment and psychiatric functioning than the standard patients. Third, while matched and standard patients had sizable and equivalent improvements on most measures of alcohol and drug use, matched patients were less likely to be retreated for substance abuse problems during the six-month follow-up. These findings suggest that matching treatment services to adjunctive problems can improve outcomes in key areas and may also be cost-effective by reducing the need for subsequent treatment due to relapse.

Limitations of the Matching Services to Problems Approach—It is difficult to argue against the face validity of a treatment approach for polyproblem substance abusers that stresses the importance of providing additional services to address co-occurring medical, economic, psychiatric, family, and legal problems. After all, effective substance abuse focused interventions such a Cognitive Behavioral Therapy or Twelve Step Facilitation (Project MATCH, 1997), no matter how well delivered, are not designed to address serious problems in other areas. If left untreated, co-occurring problems can increase risk for poor treatment response and poor posttreatment outcome. And in some cases, it may be impossible to even initiate treatment for a substance abuse problem until treatment for a severe co-occurring problem has been provided. In addition to benefits for the patients, the matching services to problems approach can also reduce stress levels in clinicians who treat polyproblem individuals, provided that a team approach to treatment is taken and regular lines of communication are established between clinicians involved with a case.

The primary limitation of this approach concerns the potential lack of resources in a time of health care cost containment. Funding may not be available to substance abuse treatment providers for adjunctive services in areas such as medical and psychiatric care, unless the level of problem severity is high enough that these co-occurring disorders can be considered as "primary." Recent research has shown that substance abuse programs vary widely in the number and frequency of adjunctive services they provide (D'Aunno and Vaughn, 1995; McLellan et al., 1993a; Widman et al., 1997), which may reflect differences between programs in the funding available for such services. Obviously, it is impossible to match services to problems if the appropriate services are not available. The scarcity of resources underlies the need for accurate assessment and diagnosis of co-occurring problems, so as to ensure that patients who are more in need of such services will stand a better chance of receiving them. Also, not all services may be potent enough to make a significant impact on the target problem area. For example, despite the importance of employment related problems in predicting treatment outcome, and the range of interventions that have been developed to improve employment and self-support among substance dependent patients (see French et al., 1992), there is little evidence that this type of specialized service is effective in improving the employment of the patients or in improving abstinence from drugs (Hall et al., 1981 is an exception).

Another potential problem with the matching services-to-problems approach is that even when adjunctive services are available in the community, they may not be offered at the clinic or agency in which the patient is receiving substance abuse focused treatment. In cases where patients have to go to other agencies to obtain additional services, there is a greater chance of attrition due to logistical problems or flagging motivation. This is a strong argument for combining substance abuse treatment with a broader array of services, which is sometimes referred to as "one-stop shopping," in settings where a more interdisciplinary approach can be taken for the treatment of the polyproblem individual.


In the text above we have attempted to review the substance abuse treatment research literature to identify patient and treatment process variables that have been shown to be important in determining outcome from addiction rehabilitation efforts; and in this way to contribute to the discussion of what treatment research may offer to practitioners in the field. While it is true that many of the research studies reviewed employed highly selected patient samples and/or sophisticated, resource-intensive interventions that would not be practical in "real world" community treatment programs, it is also true that this literature offers some important starting points for our larger effort to fill the gaps between what is known and what needs to be known at the level of the treatment program. This in turn is important for identifying clinical and policy issues that should be the focus of future research. Our review of this research has suggested the following three points:


The existing literature on treatment outcomes has been disappointing with regard to informing treatment practice at the level of the community treatment program. Most of the outcome studies in the current literature were conducted by clinical researchers, typically in controlled trials. The purpose of these studies was generally to determine whether the index treatment, when delivered under specified conditions to rather highly selected samples of patients, could effect the expected changes relative to standard or minimal treatment conditions. Many of the clinical trials reviewed here excluded important classes of patients (e.g., polysubstance users) that are most prevalent in community treatment agencies. In addition, many of these studies used very specific, resource-intensive interventions studied under rarefied conditions for fixed periods of time. In most clinical practice settings, when a patient fails to respond to one type of intervention, the sensitive clinician will alter the approach. Thus the interventions that are compared in experiments may not reflect what happens in practice.


Despite these caveats, there are important findings from controlled clinical research that suggest important directions for treatment practice in the "real world"—Given a definition of good outcome from rehabilitation treatment as "lasting improvements in those problems that led to the treatment admission and that were important to the patient and to society," the following patient and treatment process factors have been significantly and repeatedly related to favorable outcomes.

  1. Patient variables associated with better outcome from rehabilitation included:

low severity of dependence,


few psychiatric symptoms at admission,


motivation beyond the precontemplation stage of change,


being employed or self supporting, and


having family and social supports for sobriety.

  1. Treatment variables associated with better outcome from rehabilitation included:

staying longer in/ being more compliant with treatment—especially through behavioral contracting for positive reinforcement;


having an individual counselor or therapist;


having specialized services provided for associated medical, psychiatric, and/or family problem;


receiving proper medications—both for psychiatric conditions and anticraving medications; and


participating in AA or NA following treatment.

  1. In contrast to the above findings, it was surprising that some of the treatment elements that are most widely provided in substance abuse treatment have not been associated with better outcome. For example, our review of the literature has shown little indication that any of the following lead to better or longer lasting outcomes following treatment:

alcohol/drug education sessions;


general group therapy sessions, especially "confrontation" sessions;


acupuncture sessions;


patient relaxation techniques; and


treatment program accreditation or professional practice certification criteria.

  1. For the sake of brevity, studies of these five interventions were not described above. These findings are generally in accordance with a review of the alcohol rehabilitation field by Miller and Holder (1994), which concluded that there are a number of therapeutic practices and procedures that remain prevalent in the field that have not yet shown indication of success. It is important to note that "the absence of evidence" does not prove a treatment element is ineffective. Some of the treatment practices or conventions cited may actually have benefits for some patients or under some circumstances but we have found little support for these in the existing literature.

A reviewer of this field will get substantially different views about the "outcome" of an addiction treatment depending upon the perspective taken regarding what "outcome" is; and when, how, and by whom it is measured. Consider three common perspectives on the evaluation of an outpatient addiction treatment program. A quality assurance or service delivery evaluation of that treatment might conclude that the program "had very good outcomes" since there was no waiting for treatment entry and at discharge, more than 80% of the patients were "highly satisfied'' with their counselor and physician. A clinical researcher, having interviewed a sample of patients at admission to the program, and again six months following discharge, might conclude that the program "had mixed outcomes" since at the follow-up point, only 50% of the patients were abstinent (the intended goal of the program) but there was a 70% reduction in frequency of drinking and a 50% reduction in medical and psychiatric symptoms. Meanwhile, an economist or health policy analyst might have used Medicaid data tapes to compare the health services utilization rates of a sample of discharged patients, two years prior to their treatment admission and two years following their discharge. The conclusion here might be that "treatment had very poor outcome" since there had been no decrease in health care utilization from the pre- to the posttreatment period, hence no "cost-offset" to the public.

This example illustrates two points. First, that these three common perspectives on outcome have different purposes for their evaluations and different expectations regarding treatment, they measure different elements of the treatment process and the patient population, and at different points in time. Following from the first point, these different measures of outcome are not well related to each other; and it has been the case that clinical research has often focused upon a rather narrow set of outcomes (e.g., abstinence from alcohol or drugs) to evaluate treatments while interventions delivered at community treatment organizations are being evaluated on a different and often broader set of outcomes (e.g., reduction of crime, reincarceration, reduction of family violence, reduction of Medicaid claims, etc.). If research is to be able to inform clinical practice, there should be efforts made to agree upon and adopt common expectations and measures.


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Supported by grants from the National Institute on Drug Abuse, the Center for Substance Abuse Treatment, and the Robert Wood Johnson Foundation. Parts of this paper appear in McKay and McLellan, 1997 and an earlier IOM report on Managing Managed Care, 1997.

Copyright 1998 by the National Academy of Sciences. All rights reserved.
Bookshelf ID: NBK230395


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