A systematic review including 10 RCTs with a total of 1 500 subjects was abstracted in DARE. The patients had treatment-resistant major depressive disorder. Studies assessed adjunctive treatment with an atypical antipsychotic such as olanzapine, quetiapine and risperidone combined to standard antidepressants. The response was evaluated by either Hamilton Rating Scale for Depression (HAM-D) or the Montgomery-Asberg Depression Rating Scale (MADRS) during the follow-up from 4 to 12 weeks. Augmentation of standard antidepressants was associated with an increase in remission (RR 1.75, 95% CI 1.36 to 1.63) and response rates (RR 1.35, 95% CI 1.13 to 1.63). Treatment with antipsychotics was associated with a higher rate of discontinuation due to adverse events (RR 3.38, 95% CI 1.98 to 5.76). However, there was no difference between groups in terms of the overall discontinuation rate (RR 1.18, 95% CI 0.93 to 1.49) or rate of discontinuation due to inefficacy (RR 0.66, 95% CI 0.39 to 1.13).
Comment: The quality of evidence is downgraded by indirectness (short follow-up).