Early improvement is a predictor of treatment outcome in patients with mild major, minor or subsyndromal depression.

BACKGROUND There is substantial evidence that early improvement (EI) under antidepressant treatment is a clinically useful predictor of later treatment outcome in patients with major depressive disorders. The aim of this study was to test whether EI can also be used as a predictor for treatment outcome in patients with mild major, minor or subsyndromal depression, i.e. patients, who are typically treated by general practitioners. METHODS Analyses were carried out using data from 223 patients of a 10-weeks randomized, placebo-controlled trial comparing the effectiveness of sertraline and cognitive-behavioural therapy (CBT) in patients with mild major, minor or subsyndromal depression. EI was defined as a reduction of > or =20% on the 17-item Hamilton Rating Scale for Depression (HAMD-17) compared with baseline within the first 2 weeks of treatment. The predictive value of EI for stable response at week 8 and 10 (> or =50% HAMD-17 sum score reduction at weeks 8 and 10) and stable remission (HAMD-17 sum score < or =7 at weeks 8 and 10) was evaluated. RESULTS In both the sertraline- and CBT-treatment group, EI was a highly sensitive predictor for later stable response (76% and 82%, respectively) and stable remission (70% and 75%, respectively). In patients without EI, only a small proportion of sertraline or CBT-treated patients achieved stable response (20.9% and 5.9%, respectively) or stable remission (18.6% and 8.8%, respectively). Patients with EI were by far more likely to achieve stable response or stable remission than patients without as indicated by high odds ratios (95% confidence interval) of 8.1 (3.0-21.8) and 3.8 (1.4-10.1) for sertraline, and 11.1 (2.1-58.4) and 7.2 (1.7-30.8) for CBT-treated patients, respectively. LIMITATIONS Sample sizes were relatively low in different treatment groups. CONCLUSION The identification of early improvement might be useful in clinical decision making in the early course of treatment of patients with mild major, minor and subthreshold depression.