Using the psychotherapy dosage model in which effect was probability of recovery, this study compared treatment response rates for psychological symptoms. Symptom checklists were administered to 854 psychotherapy outpatients at intake and during treatment. Sixty-two symptoms were grouped into 3 classes on the basis of probit analysis results. Chronic distress symptoms demonstrated the fastest average response rate, whereas characterological symptoms demonstrated the slowest. Acute distress symptoms showed the highest average percentage of patients recovered across doses. A typical outpatient needed about a year of psychotherapy to have a 75% chance of symptomatic recovery. The model holds promise for establishing guidelines for the financing of psychotherapy.