[Major depressive episode: a study of remission and relapses].

Background: Our objective was to study the rates of remission and relapse over more than two years in a sample of Spanish outpatients with DSM-III-R criteria of unipolar major depressive episodes.

Patients And Methods: In the first assessment, we used the structured clinical interview for DSM-III-R (SCID). Forthcoming visits were held monthly. A survival analysis was used to assess partial and complete remission in the original sample of 356 patients. The probability and prediction of relapses were calculated in 186 patients who finished the 2 year follow-up period. Evolution stages were recorded using the Hamilton Depression Rating Scale (HDRS), after applying the Frank criteria. Patients were treated following standardized pharmacological protocols at our center.

Results: After 6 months of follow-up, 50% of patients had attained a complete remission; it was partial in 25% of cases. Rate of relapses for patients on complete remission was 12,18%, whereas it was 67,61% for patients on partial remission. Risk of relapses was 2,84 times greater after partial remission than after complete remission. Partial remission was the most powerful predictor of relapses.

Conclusions: Partial remission after a depressive episode seems to be an important predictor of relapses.