Clinical differences between early and late remission in depressive patients.

Abstract Objective Predicting treatment outcome at an early stage is clinically relevant. The main objectives are: to compare rates of remission after acute and continuation phase treatment and to determine the most common residual symptoms among remitted patients; to compare the residual symptoms in early and late remitted and to identify factors that predict early or faster remission. Method It is a prospective, naturalistic, multicenter, and nationwide epidemiological study of 1595 depressive outpatients. Severity of depressive symptoms was assessed with the Hamilton Depression Rating Scale (HDRS) and the Self Rated Inventory of Depressive Symptomatology (IDS-SR 30 ). Assessments were carried out after 6–8 weeks of antidepressant treatment and after 14–20 weeks of continuation treatment. Early remitters were defined with an IDS-SR 30 score ≤ 14 at first and second assessment. Late remitters were defined as those scoring IDS-SR 30 > 14 at first and IDS-SR 30 score ≤ 14 at second assessment. Results 140 subjects (8.8%) were in remission after 6–8 weeks of antidepressant treatment and 862 remitted (59%) after 16–20 weeks of treatment. The mean number of residual symptoms is significantly higher among patients who remit later. Greater differences between early and late remitters were found in the following symptoms: feeling sad, reactivity of mood, interpersonal sensitivity and pleasure/enjoyment. Multivariate analysis showed that only comorbid anxiety disorder is significantly associated with late remission. Conclusions Early remitted patients have a better “quality” of remission. Late remission is associated with residual symptoms more related to core depressive symptoms. Residual symptoms in early remitted patients may constitute a new target for the treatment of depression.