Functional impairment in patients with major depressive disorder and comorbid anxiety disorder

Abstract

Objective: To analyze the potential for different aspects of anxiety to modify the effect of impaired functioning in major depressive disorder (MDD). Methods: Participants (n = 1226) were psychiatric outpatients with MDD. A cross-sectional, multicentre, nationwide study was designed. The 12-item version of the World Health Organization Disability Assessment Schedule II was used to assess functional limitation. Anxiety was measured using the Hamilton Anxiety Rating Scale and the State-Trait Anxiety Inventory (STAI). Depression severity was measured using the Quick Inventory of Depressive Symptomatology. Results: About 43.1% of patients had a comorbid MDD and anxiety disorder. Poorer functioning correlated significantly with severity of depression (Pearson r = 0.78, P = 0.001), severity of anxiety (r = 0.65, P = 0.001), and higher anxiety trait scores (r = 0.40, P = 0.001), but not significantly with STAI-State scores (r = 0.03, P = 0.26). The overall regression model was significant and explained 66% of the functioning variability in patients with MDD, mostly attributable to depression severity. Results indicate that anxiety has a moderate impact on functioning impairment in patients with MDD. Conclusions: Our findings suggest that MDD and anxiety severity appear to be associated significantly with impaired functioning in patients with MDD but explains only a moderate proportion of variance.