Association between antidepressant side effects and functional impairment in patients with major depressive disorders

Patients with depression may not well be aware of antidepressant adverse events (AEs); however, no studies have assessed how these AEs affect their daily function. Therefore, to evaluate the relationship between the quality of AEs and functional impairment, we studied 482 outpatients with depressive disorders who were not receiving any antidepressant treatment prior to the baseline visit and started it thereafter in usual clinical settings. The Quick Inventory for Depressive Symptomatology Self-Report Japanese version and antidepressant AEs for subjective assessment (antiAS) were performed at baseline and 10 days after antidepressant initiation (i.e. second visit). Functional impairment was evaluated with the Sheehan Disability Scale (SDS) on the second visit. As a result, the SDS was positively associated with the number of AEs (β=0.089, p=0.022) in multiple linear regression analysis (adjusted R²=0.357, p<0.001). Subjects who experienced vertigo, nausea and insomnia had significantly more functional impairment than those who did not. Additionally, the number of severe AEs (β=0.151, p<0.001) was associated with a higher SDS score, and those AEs with a negative causal attribution to antidepressants in the antiAS significantly affected the SDS (β=0.105, p=0.008). AEs of antidepressants should be carefully monitored since they could negatively affect their daily function.