Effect of augmented atypical antipsychotics on weight change in patients with major depressive disorder in a naturalistic setting

Objective: The extent of weight changes in depressed patients who use atypical antipsychotics (AAP) as augmentation could not be easily predicted due to weight related symptoms of depression and the interaction with antidepressants which have weight reducing effects. Methods: Patients were treated with either antidepressants augmented with AAF for more than 2 weeks (AAP group, n = 100) or only with antidepressants (non-AAP group, n = 172) during the admission between 2002 and 2006, and the differences in weight were analyzed. Results: Mean weight gains of AAP group were significantly higher than those of non-AAP group (2.98 ± 1.87 kg vs. 1.70 ± 1.85 kg, p = 0.001). When stratified by antidepressants, the significant difference between the two groups was shown among the subjects who had taken serotonin reuptake inhibitors (SSRIs), but not mirtazapine and venlafaxine (3.42 ± 2.01 kg vs. 1.48 ± 1.79 kg, p < 0.001). Comparing among different combinations in AAP group showed that subjects treated with SSRIs and olanzapine had the greatest weight gain (4.21 ± 1.90 kg), significantly higher than that of the other subgroups (p < 0.001). Conclusions: Our findings suggest that AAP used in patients with depression could severely aggravate preexisting weight-related problems of antidepressants use and the possibility that the combined use with specific antidepressants could have a unique effect on weight by drugdrug interactions.