Ranking the correlates of psychotherapy duration.

This study examined the relative strength (importance) of associations between the number of treatment sessions in mental health clinics and some pretherapy (e.g., payer source), treatment (e.g., use of medication), and outcome (e.g., improvement) variables. Data on clients who withdrew prematurely (dropouts) and data on those discharged by counselors (completers) were compared. A combined sample that included both groups of clients was also examined. The strongest correlates of the number of sessions were treatment outcome (for the combined sample) and the identity of the counselor (for clients who completed treatment). No leading predictor for the dropout group was found. Results of the study suggest that different factors may emerge as the most important correlates of the number of treatment sessions, depending on whether dropouts, completers, or both are included in the sample.