BACKGROUND: Telephone-administered psychotherapies (T-P) provided as an adjunct to antidepressant medication may improve response rates in major depressive disorder (MDD). The goal of this study was to compare telephone-administered social rhythm therapy (T-SRT) and telephone-administered intensive clinical management (T-ICM) as adjuncts to antidepressant medication for MDD. A secondary goal was to compare T-P with Treatment as Usual (TAU) as adjunctive treatment to medication for MDD. METHODS: 221 adult out-patients with MDD, currently depressed, were randomly assigned to 8 sessions of weekly T-SRT (n=110) or T-ICM (n=111), administered as an adjunct to agomelatine. Both psychotherapies were administered entirely by telephone, by trained psychologists who were blind to other aspects of treatment. The 221 patients were a posteriori matched with 221 depressed outpatients receiving TAU (controls). The primary outcome measure was the percentage of responders at 8 weeks post-treatment. RESULTS: No significant differences were found between T-SRT and T-ICM. But T-P was associated with higher response rates (65.4% vs 54.8%, p=0.02) and a trend toward higher remission rates (33.2% vs 25.1%; p=0.06) compared to TAU. LIMITATIONS: Short term study. CONCLUSIONS: This study is the first assessing the short-term effects of an add-on, brief, telephone-administered psychotherapy in depressed patients treated with antidepressant medication. Eight sessions of weekly telephone-delivered psychotherapy as an adjunct to antidepressant medication resulted in improved response rates relative to medication alone.