Relationship between Prosocial Behaviours and Addiction Problems: A Systematic Review

The relationship of addiction problems with other pathologies or with different problematic factors has often been studied by psychology. Positive psychology is also currently approaching to these problems and their relationship with positive factors, such as prosocial behaviours. The purpose of this research is to carry out a systematic review of the scientific literature that has studied this relationship from 1900 to 2020. After the screening process with the inclusion and exclusion criteria, a total of 15 articles were selected. The main characteristics found in this relationship and the problems or limitations of investigations that have found relationships other than the mainstream, which show a negative relationship between prosocial behaviours and addiction problems, are discussed.


Introduction
Research on addiction problems has often been focused on their relationship with other psychological disorders by the field of psychology. Depression, one of the psychological disorders affecting more people today, has been shown to be related to both substance addiction [1] and addictive behaviours, such as social media addiction [2]. In the case of anxiety, another widespread mental disorder, the same relationship as in the case of depression has been found with both addictive behaviours [3] and substance addiction [1].
Another relationship that has been widely studied is the one that addiction problems keep with what is considered negative personality traits. Research on the relationship between addictions and antisocial behaviours has found that problematic alcohol consumption in adolescence is associated with antisocial behaviours in adulthood [4]; the use of other addictive substances, such as cannabis and tobacco, also appears to be directly related to these behaviours [5]. In the case of addictive behaviours, research suggests a similar relationship. For example, Pivetta, Harkin, Billieux, Kanjo, and Kuss [6] reported that smartphone addiction was directly related to antisocial behaviours. Other traits, such as low self-esteem [7] or lack of empathy [8,9], are directly related to addiction problems, too.
The concept of positive psychology emerged in the late 1990s [10] to name a stream of psychology that sought to find, develop, and evaluate interventions focused on enhancing positive aspects and human well-being rather than focusing on pathologies, negative aspects, or problems [11]. This stream arises from the basis that psychopathologies and well-being are independent constructs but closely related [12]. Positive psychology aims to enhance aspects such as optimism, personal growth, forgiveness, enjoying good things, or being grateful for positive experiences, among others [13].
Prosocial behaviour is closely linked to positive psychology [14] and is one of the aspects to be enhanced to improve people's well-being [15]. These behaviours aim to help others and are beneficial to them, helping to avoid antisocial behaviours or aggressive Healthcare 2022, 10, 74 2 of 17 attitudes [16,17]. As a consequence of this characterization of prosocial behaviour, it is apparently incompatible that prosocial behaviours coexist with behaviours that decrease the expression of prosociality. This is the case with addictive behaviours. Addictive behaviour becomes the main focus of a person's life, excluding other activities, or begins to harm the individual and others physically, mentally, or socially.
The study of addictions from the positive psychology point of view, specifically the relationship of addictions with prosocial behaviours, lacks extensive research, especially when compared with the previously indicated research of pathologies, negative personality traits, or interpersonal relationships. The absence of extensive research is not clear, but it is possibly driven by intuitive reasoning that both must covariate negatively due to the apparent incompatibility between them. However, this gap is an opportunity to show patterns of scientific findings that may have theoretical and applied value.
Existing research finds a two-way relationship in which prosocial behaviour acts as a protective factor against the development of addiction problems [18,19]. On the other hand, people with addiction problems tend to carry out fewer prosocial behaviours than those who do not have these problems [20,21]. It is important to note that many of these investigations focus on adolescents and not adults.
The aim of this research is to carry out a synthesis of the existing information in the existing literature on the relationship between prosocial behaviours addiction problems in adults, whether they are addictions to substances or behaviours, to know the current state of the research about this theme.

Methods
A systematic review (SR) was carried out after the recommendations of the PRISMA guideline [22] for this type of research. Appendix A includes a checklist following the PRISMA guide. In addition, a bibliometric analysis of the documents selected after the screening process was carried out.
First, a search in the Tripdatabase and Cochrane databases was performed to verify that there were no previous SR or meta-analysis that had already investigated this relationship. This was followed by a search in the Web of Science (WoS; main collection), Scopus, PsycInfo, and Dialnet databases.
The purpose was to search for "prosocial behaviour". However, this term appears in the scientific literature with many synonyms, such as "prosociality". The word prosocial* was included in the search equation since it is the root of the word prosocial. In screening, eligibility, and inclusion, all those articles that evaluated prosocial behaviour were eliminated.
The search equation used in WoS was Prosocial* AND (Gambl* OR Addict* OR "Substance Abuse" OR Drug*), and it was therefore adapted for the rest of the databases. In the case of Dialnet, the search equation was written in Spanish and was the following: Prosocial* AND (Ludopati* OR Adic* OR Abuso OR droga*). Finally, a complementary search was done in Google Scholar to include grey literature and avoid the possible publication bias.
The search was made in titles, abstracts, and keywords, and no restriction was included for years. Thus, it covers from 1900 to July 2021 (however, no documents prior to 1991 were found). Only empirical research articles were selected. After removing duplicate records, the total number was 815.
These 815 selected articles were analysed in two steps. In the first one, only the title and abstract of the documents were read. The complete document was read in the second one. The screening process was carried out on the basis of the following criteria: (a) Documents should be written in English or Spanish, excluding any other language. (b) Documents should be empirical research articles with quantitative method. Books, doctoral theses, editorials, lectures, clinical case studies, literature reviews, and other research with non quantitative method were discarded. (c) Investigations should be conducted on humans; animal investigations were excluded.
(d) The addiction problems analysed should be present in adults. Articles that studied the effect of prosocial behaviours in adolescence or childhood on addiction problems in adulthood were also selected. Investigations that focused on the problems of addiction in minors were discarded. (e) Documents that analysed the relationship between prosocial behaviours and addictions were selected. Those that did not analyse this relationship were discarded. We also ruled out research that analysed prosocial jobs, prosocial attachments, or prosocial environments instead of prosocial behaviours. (f) All documents focusing on the neurobiological basis of addictions and the effect of drugs or treatments without focusing on the relationship between prosocial behaviours and addiction problems were discarded.
The selection and screening process of documents is detailed in Figure 1.
(a) Documents should be written in English or Spanish, excluding any other language. (b) Documents should be empirical research articles with quantitative method. Books doctoral theses, editorials, lectures, clinical case studies, literature reviews, and other research with non quantitative method were discarded. (c) Investigations should be conducted on humans; animal investigations were excluded. (d) The addiction problems analysed should be present in adults. Articles that studied the effect of prosocial behaviours in adolescence or childhood on addiction problems in adulthood were also selected. Investigations that focused on the problems of addiction in minors were discarded. (e) Documents that analysed the relationship between prosocial behaviours and addictions were selected. Those that did not analyse this relationship were discarded. We also ruled out research that analysed prosocial jobs, prosocial attachments, or prosocial environments instead of prosocial behaviours. (f) All documents focusing on the neurobiological basis of addictions and the effect of drugs or treatments without focusing on the relationship between prosocial behaviours and addiction problems were discarded.
The selection and screening process of documents is detailed in Figure 1.

Results
A total of 15 documents that met the criteria were found to be part of the review. Table 1 shows the main characteristics of the 15 documents sorted alphabetically by authorship.
First, all the articles analysed were published in the last 20 years: 80% in the last 10 years and 53.3% of them originating within the last five years (taking into account that at the time of this review, the year 2021 has not yet been completed, and the number of articles published during that year may increase). Moreover, 40% (n = 6) of the investigations were carried out in the USA; 40% were in Spain, China, and Switzerland (n = 2 for each country); and the remaining 20% were done in England, the Netherlands, and Canada (n = 1 for each country).
With regard to the characteristics of the studies, 86.6% (n = 13) of them applied validated instruments to measure the participants' prosocial behaviours, while 60% (n = 9) applied validated instruments or performed biological tests to measure substance use or addiction problems. Only two studies [23,24] included groups of participants with diagnosed addiction problems, representing 13.3% of the total articles analysed in the review.

Results
A total of 15 documents that met the criteria were found to be part of the review. Table 1 shows the main characteristics of the 15 documents sorted alphabetically by authorship.
First, all the articles analysed were published in the last 20 years: 80% in the last 10 years and 53.3% of them originating within the last five years (taking into account that at the time of this review, the year 2021 has not yet been completed, and the number of articles published during that year may increase). Moreover, 40% (n = 6) of the investigations were carried out in the USA; 40% were in Spain, China, and Switzerland (n = 2 for each country); and the remaining 20% were done in England, the Netherlands, and Canada (n = 1 for each country).
With regard to the characteristics of the studies, 86.6% (n = 13) of them applied validated instruments to measure the participants' prosocial behaviours, while 60% (n = 9) applied validated instruments or performed biological tests to measure substance use or addiction problems. Only two studies [23,24] included groups of participants with diagnosed addiction problems, representing 13.3% of the total articles analysed in the review. Public prosocial behaviour is a positive predictor of alcohol consumption (self-oriented for the approval of others, not altruistic); cannabis use is a negative predictor of anonymous prosocial behaviour (altruistic, other-oriented)

Authors (Year) and Country Studied Addiction and Aims Sample Design Method Results
Esparza-Reig (2020); Spain [32] Gambling addiction; To deepen the study of prosocial behaviour in young university students to better understand its functioning and its effects on the development of gambling addiction problems Prosocial behaviour is a protective factor against both gambling addiction problems and problematic alcohol use Fenzel (2005); USA [36] Alcohol; To examine a set of personality, environment, and risk and protective factors that are expected to be related to the frequency of binge drinking and alcohol-related problems in university students n = 686 (472 women); 19.6 years (1.2); university students (general population)

Cross-sectional
To measure the frequency of binge drinking in the last two weeks, an item was applied, and a series of items of 3 alternatives that measured whether alcohol consumption had caused them different problems; to measure prosocial behaviours, the number of behaviours of this type carried out by the participants was consulted Prosocial behaviour is a protective factor against the frequency of binge drinking and the problems derived from this behaviour The group that decreased consumption and control was closer in their scores in prosocial behaviour after one year; those that increased the use of cocaine maintained the distance in the levels of prosocial behaviour with the control group With regard to the addictions studied, the 15 articles analysed 29 relationships between a certain addiction and prosocial behaviour because some articles investigate the relationship with several addictions or the same relationship in different samples. Of these 29, 58.62% (n = 17) focused on the relationship between prosocial behaviours and substance addiction problems and 41.37% (n = 12) on the relationship between prosocial behaviour and addictive behaviours. In the case of addictive behaviours, the most studied (n = 7) was the addiction to video games, representing 24.13% of the relationships studied, while 13.79% (n = 4) analysed the relationship between prosocial behaviour and gambling. On the other hand, accordingly to the substance of abuse, the most studied were the addiction to alcohol (n = 7) and to cannabis (n = 5), with 24.13% and 17.24%, respectively. The next most studied addictive substance was tobacco (n = 3), and finally, 3.44% analysed the relationship with cocaine (n = 1). In the case of Moilanen and Lynn [44], the relationship between prosocial behaviour and substance abuse was studied, but no specific substance was specified.
Regarding the results of the relationships studied in isolation for each substance or addictive behaviour with prosocial behaviour, it was found that, in the case of videogaming addiction, 6.89% of the relationships investigated (n = 2) found that this addictive behaviour correlated negatively with prosocial behaviour [43]. Another 10.34% did not find any relationship between problematic video-gaming and prosocial behaviour [27,37]. The relationship between prosocial behaviour and gambling was only analysed once [32], finding that both correlated negatively, with prosocial behaviour being a protective factor against gambling problems.
In the case of the relationship between cannabis use and prosocial behaviours, 10.34% (n = 3) of the results show that both variables are negatively related, while 3.44% (n = 1) reflected a positive relationship, and another 3.44% (n = 1) found no significant differences [50]. In particular, the results showed that prosocial behaviour during adolescence acts as a protective factor against problematic cannabis consumption in adulthood [25] and that cannabis users showed less prosocial behaviour in adulthood [23,30]. On the other hand, prosocial behaviour in childhood would lead to increased cannabis use in adulthood [45].
Overall, 6.89% (n = 2) of the research results show that prosocial behaviour during adolescence [25] and during adulthood [36] functions as a protective factor against problematic alcohol consumption in adulthood. Of the remaining results, 13.79% (n = 4) found no relationship between prosocial behaviour in childhood [45] and anonymous prosocial behaviour, e.g., altruistic and focused on others without seeking a reward [36], and problem alcohol use in adults. Davis et al. [30] found a positive relationship between alcohol consumption and prosocial behaviour, but in this case, it was a type of public behaviour focused on what others would think, which would not fit into the altruistic approach of prosocial behaviour.
Regarding research on the relationship of prosocial behaviour and tobacco use, 3.44% (n = 1) found that prosocial behaviours during adolescence acted as a protective factor against tobacco consumption in adulthood [25]. Of the remaining articles, 6.89% (n = 2) found no relationship between tobacco use and prosocial behaviour [45].
In the case of cocaine, only one study analysed the link between cocaine use and prosocial behaviour [24] and found that both correlated negatively so that the people who consumed the most had greater deficits in their prosocial behaviour. Finally, Moilanen and Lynn [44] found no relationship between prosocial behaviour and substance abuse, without specifying which substances were involved.
When making no distinctions between the specific addiction studied, 20.68% (n = 6) of the results in the investigation between addictive behaviours and prosocial behaviour found a negative relationship. Of this proportion, 17.24% (n = 5) found that both variables correlate negatively, and the remaining 13.79% (n = 4) found that prosocial behaviours were a protective factor against addiction problems. In the case of substance addictions, 31.03% (n = 9) found a negative relationship with prosocial behaviours, 6.89% (n = 2) found a positive relationship, and the remaining 20.68% (n = 6) did not find a relationship. Of the 31.03% that found a negative relationship, 6.89% (n = 2) identified prosocial behaviours as a protective factor against substance addiction problems, while the remaining 3.44% (n = 1) identified substance addiction problems as a predictor of lower levels of prosocial behaviour.
When a distinction between addictive behaviours and substance addiction was not made, the 51.72% of the results (n = 15) found a negative relationship between addiction problems and prosocial behaviours, 6.89% (n = 2) a positive relationship, and 34.48% (n = 10) found no relationship. Of the 51.72% of results with a negative relationship, 6.89% (n = 2) did not analyse if one of the two exerted as predictor of the other, 20.68% (n = 6) placed addiction problems as predictors of fewer prosocial behaviours, and 24.13% placed prosocial behaviours as a protective factor against addiction problems.

Discussion
The aim of this research was to carry out a systematic review of the literature that has studied the relationship between prosocial behaviours and problems of addiction in adults either to substance addiction or addictive behaviour. The last aim was to know the current status of the investigation with regard to this relationship.
First, the results show that this relationship has not been very analysed over the years, but it has begun to gain relevance in recent years (especially in the last decade). The majority of the research is concentrated in USA, but it has also been studied in more countries.
On the other hand, despite the fact that most of the research used validated tests or medical analysis to measure the levels of prosocial behaviour or addiction problems (5.12% and 33.33% of the research, respectively), there is still a significant percentage of studies that does not use them, which is something to take into account for the results' interpretation. In addition, it is noteworthy that only 20% of researches include participants with diagnosed addiction problems, while most of them are focused on a population without specific problems, which is also a limit of the results obtained.
Regarding the type of addiction, 55.17% studied substance addictions, and 44.82% focused on addictive behaviours, which can be considered quite balanced. Among addictive substances, studies are centred mainly on alcohol and cannabis, accounting for 37.93% of research, while in addictive behaviours, the most studied is the video-gaming addiction, with 24.13% of the total.
Focusing on the relationship between prosocial and addictive behaviour, the results mainly give back a negative relationship between both variables. However, 13.79% (n = 4) of the research does not find any relationship. It should be noted that one of the two investigations that found this lack of relationship [37] did not apply any instrument to assess the prosocial behaviour, and it was limited to one item. The other study that found no relationship [27] points out in the limitations that they did not analyse if video game players did it in isolation or with friends, so they recommend taking this aspect into account when interpreting the results of their research.
On the other hand, in the case of the analysis of the relationship between prosocial behaviours and substance addiction, it is also reflected that there is a negative relationship between the two variables regardless of the substance of abuse. However, there are studies that have found that this relationship is positive (6.89% of the total) or have found that there is no such relationship (20.68%). When analysing the characteristics of these articles, it should be noted that Quigley and Maggi [45] found a positive relationship, but they studied the consequences of prosocial behaviours during childhood on the problems of cannabis use in adulthood, and they did not apply any instrument or validated test to measure the variables (all data are self-reported). In addition, these same authors found that prosocial behaviour in childhood was not related to alcohol and tobacco consumption in adulthood, and therefore, the same limitations already set out on this investigation should be taken into account when interpreting these results.
With regard to the direction of the relationship between prosocial behaviours and addiction problems, 13.79% of the research argues that prosocial behaviours are a protective factor against problems of addiction to gambling, while 20.68% argues that addiction problems are what cause deficiencies in prosocial behaviours. These results are not contradictory since it may be the case that prosocial behaviours truly are a protective factor but, in turn, develop addiction problems that generate negative effects on behaviours towards others.

Limitations
We must highlight some limitations. First, and which is possibly the main limitation of this systematic review, is the number of investigations analysed, which decreases its capacity for generalization. Second, most of the research was done in the USA, which skews the results toward English-speaking populations. Third, the use of valid measuring instruments in only 38.46% of the relationships weakens the results of studies where the validity of the measurement is induced or unknown. Fourth, correlational studies allow us to recognise relationships, associations, or simultaneous presence of variables, but they do not allow us to point out causes and effects between addictions and prosocial behaviour. Fifth, the size of the selected studies was generally small, which does introduce significant variations due to the size of the sampling error. Finally, it is considered important to point out that it was not possible to assess the quality of the studies that were included in the review due to the fact that there were only a limited number.

Practical Implication
The initial results allow us to encourage the use of programs and volunteering that help in the development of prosocial behaviours both with children and adults. Furthermore, the use of valid instruments for the measurements of all variables to be investigated is pointed out.

Future Research Lines
First, more research is needed to study the relationship between prosocial behaviours and addictions in different countries and different social, gender, and age groups as well as to isolate different addictive substances and behaviours. Second, the exploration of the relationships between these constructs was focused exclusively on linear dependency, completely ignoring the possible and reasonable existence of non-linear associations. Therefore, it may be necessary to introduce procedures sensitive to non-linear associations. Third, there is also a need for research to use standardised, valid, and reliable measurement and evaluation instruments to ensure that what is being studied is properly analysed. In this sense, the incorporation of minimum evidence of validity of the instruments in substantive investigations (i.e., non-psychometric) is required, especially the evidence of internal structure and reliability.

Conclusions
The review shows that the relationship between prosocial behaviour and addiction problems has not yet been thoroughly researched, and although the results seem to indicate that it does exist regardless of the type of addiction, further analyses are necessary in order to reach more concrete conclusions. The strength of the relationship ranged from moderate to small. Evidence for relationships was obtained predominantly from cross-sectional research designs. There was a low proportion of studies that induced the validity of the instruments used, and this could generate measurement bias. Researchers studying this topic are encouraged to use validated instruments and tests or objective medical tests in the case of addictions as well as to include groups of participants with specific addiction problems in their research.  Specify the methods used to decide whether a study met the inclusion criteria of the review, including how many reviewers screened each record and each report retrieved, whether they worked independently, and, if applicable, details of automation tools used in the process.

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Data collection process 9 Specify the methods used to collect data from reports, including how many reviewers collected data from each report, whether they worked independently, any processes for obtaining or confirming data from study investigators, and, if applicable, details of automation tools used in the process.
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Data items 10a
List and define all outcomes for which data were sought. Specify whether all results that were compatible with each outcome domain in each study were sought (e.g., for all measures, time points, analyses), and, if not, the methods used to decide which results to collect.

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List and define all other variables for which data were sought (e.g., participant and intervention characteristics, funding sources). Describe any assumptions made about any missing or unclear information.

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Study risk of bias assessment 11 Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and, if applicable, details of automation tools used in the process.

Section and Topic Item # Checklist Item Location Where Item Is Reported
Effect measures 12 Specify for each outcome the effect measure(s) (e.g., risk ratio, mean difference) used in the synthesis or presentation of results. NA

Synthesis methods 13a
Describe the processes used to decide which studies were eligible for each synthesis (e.g., tabulating the study intervention characteristics and comparing against the planned groups for each synthesis (item #5)).

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Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics or data conversions. -13c Describe any methods used to tabulate or visually display results of individual studies and syntheses. Page 4 13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If meta-analysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used.

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Describe any methods used to explore possible causes of heterogeneity among study results (e.g., subgroup analysis, meta-regression). NA 13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results. -

Reporting bias assessment 14
Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases). -Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome. -

Study selection 16a
Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram.

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Cite studies that might appear to meet the inclusion criteria but which were excluded, and explain why they were excluded. -

Study characteristics 17
Cite each included study and present its characteristics. Pages 5-10 Risk of bias in studies 18 Present assessments of risk of bias for each included study. -

Results of individual studies 18
For all outcomes, present for each study: (a) summary statistics for each group (where appropriate) and (b) an effect estimate and its precision (e.g., confidence/credible interval), ideally using structured tables or plots.

Pages 5-10
Results of syntheses 20a For each synthesis, briefly summarise the characteristics and risk of bias among contributing studies. Pages 5-10 20b Present results of all statistical syntheses conducted. If meta-analysis was done, present for each the summary estimate and its precision (e.g., confidence/credible interval) and measures of statistical heterogeneity. If comparing groups, describe the direction of the effect.  Report which of the following are publicly available and where they can be found: template data collection forms; data extracted from included studies; data used for all analyses; analytic code; any other materials used in the review.