Dropout from individual psychotherapy for major depression: A meta-analysis of randomized clinical trials

Dropout from mental health treatment poses a substantial problem, but rates vary substantially across studies and diagnoses. Focused reviews are needed to provide more detailed estimates for specific areas of research. Randomized clinical trials involving individual psychotherapy for unipolar depression are ubiquitous and important, but empirical data on average dropout rates from these studies is lacking. We conducted a random-effects meta-analysis of 54 such studies (N=5852) including 80 psychotherapy conditions, and evaluated a number of predictors of treatment- and study-level dropout rates. Our overall weighted dropout estimates were 19.9% at the study level, and 17.5% for psychotherapy conditions specifically. Therapy orientation did not significantly account for variance in dropout estimates, but estimates were significantly higher in psychotherapy conditions with more patients of minority racial status or with comorbid personality disorders. Treatment duration was also positively associated with dropout rates at trend level. Studies with an inactive control comparison had higher dropout rates than those without such a condition. Limitations include the inability to test certain potential predictors (e.g., socioeconomic status) due to infrequent reporting. Overall, our findings suggest the need to consider how specific patient and study characteristics may influence dropout rates in clinical research on individual therapy for depression.