Prediction of efficacy of antidepressant by 1-week test therapy in depression.

Forty patients suffering from depression were treated with fixed doses of clomipramine for 4 weeks. The most effective predictor of efficacy during the 4 weeks was the percentage improvement in the Hamilton rating scale for depression during the first week. Baseline severity did not show any predictive ability. The Beck depression rating scale had only low predictive ability, and the dexamethasone suppression test did not predict the outcome at all. These results suggest the benefit of 1-week test therapy for predicting the efficacy of antidepressants.