Augmentation with atypical antipsychotics for depression: a review of evidence-based support from the medical literature.

Major depressive disorder (MDD) is a chronic mental illness that affects an estimated 5-26% of adults at some time in their lives. Treatment is often started as pharmacotherapy using a single drug such as a selective serotonin reuptake inhibitor. If a patient fails to respond adequately to the initial antidepressant, typically three pharmacotherapy options are available to the practitioner. The dose of the current therapy can be maximized, a change can be made to a different drug, or the current regimen can be augmented with another drug. Atypical antipsychotics have recently become a major focus for augmentation of traditional antidepressant therapy. This review summarizes the evidence for efficacy and safety of augmenting treatment-refractory or treatment-resistant depression with atypical antipsychotics. The National Library of Medicine's MEDLINE database was searched for all English-language articles published from January 1966-December 2011 describing the use of atypical antipsychotics in treatment-resistant depression. The literature retrieved was limited to case series, open-label trials, and randomized controlled trials (RCT). Studies of bipolar depression, psychotic depression, or studies conducted in children and adolescents were excluded. Thirty-five studies using atypical antipsychotics for augmentation treatment of depression were included in this analysis. Trials were identified for aripiprazole (six open-label; three RCT), clozapine (one case series), olanzapine (three open-label, including two case series; four RCT), quetiapine (four open-label; five RCT), risperidone (two open-label; five RCT), and ziprasidone (two open-label). The atypical antipsychotics may be effective as adjunctive therapy in MDD; however, their adverse effect profile may be unfavorable to some patients. Trying at least one alternative treatment strategy after an initial antidepressant is indicated before augmentation is implemented with these agents. If atypical antipsychotics are used, safety and efficacy should be frequently reassessed and dosage should be individualized.