Background. Dysthymia is a common mental disorder, associated with considerable disability and high co-morbidity. This review assessed the role of pharmacological treatment.

Methods. All randomized-controlled trials that compared active drug versus placebo for dysthymic patients were included. Pooled relative risks (RR) and 95% confidence intervals (CI) were calculated with the Random Effect Model method. Where possible, number needed to treat and number needed to harm were estimated.

Results. Fifteen trials were included for the main comparisons. Similar results were obtained in terms of efficacy for different groups of drugs, such as tricyclic (TCA), selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAOI) and other drugs (sulpiride, amineptine, and ritanserin). The pooled RR treatment response was 0·68 (95% CI 0·59–0·78) for TCA, 0·64 (95% CI 0·55–0·74) for SSRIs, 0·59 (95% CI 0·48–0·71) for MAOIs. Other drugs (amisulpride, amineptine and ritanserin) showed similar results. Patients treated on TCA were more likely to report adverse events, compared with placebo. There were no differences in response to active treatment when dysthymia was compared to either dysthymia plus major depression or briefer non-major depressive states.

Conclusions. Drug treatment appears to be effective in the short-term management of dysthymic disorder. The choice of drug should take into account specific side-effects profile of each drug.