The ups and downs of psychotherapy: sudden gains and sudden losses identified with session reports.

Psychotherapy does not always follow a linear path. The present study explores the frequency of sudden gains and losses during the course of outpatient psychotherapy. The sample includes 1500 patients treated at three different outpatient centers. The patients were 57.4% female, and suffered primarily from anxiety and depressive disorders. Progress was measured by session reports. Significant sudden shifts in both directions were prevalent for 28.9% of the patients. Patients with early sudden gains showed the highest effect sizes and patients with sudden losses showed the smallest at the end of treatment. The therapeutic relationship was significantly better after the sudden gain sessions. Results suggest further investigation of the occurrence of sudden gains in relation to early response as well as further exploration of sudden losses during the course of treatment with respect to differential patterns of change and outcome.