Efficacy, safety and tolerability of quetiapine augmentation in treatment resistant depression: an open-label, pilot study.

Atypical antipsychotics may have efficacy as augmentation therapy in treatment resistant depression (TRD) but evidence is limited. An open label study of quetiapine augmentation in 24 patients (mean age: 46.3 years) with a DSM-IV major depressive episode resistant to at least 2 trials of antidepressant medication, and currently taking a monoamine reuptake inhibitor. An 8-week treatment phase was followed by an 18-week extension in patients who showed clinical benefit. Eighteen patients (75%) completed the 8-week treatment phase with seven patients (29%) being responders on the Montgomery Asberg Depression Rating Scale and 13 (54%) on the CGI-I. Fewer patients responded if they had previously received olanzapine in the current episode but this was not statistically significant (0% v 37%, p=0.27). Of the eleven patients entering the extension phase, 3 patients (27%) experienced a significant worsening of mood. The most common adverse events were sedation (54%), dry mouth (38%) and dizziness (29%). Significant weight gain was found in 40% of patients treated for 26 weeks. Average quetiapine doses were 245 mg at 8 weeks and 346 mg at 26 weeks. Quetiapine may be a helpful adjunctive agent for some patients with TRD but placebo-controlled trials are needed to establish its place in management. The trial was open-label and the numbers were small.