The impact of major depressive disorder on adaptive function: A retrospective observational study

Although functional impairment is very common among patients with major depressive disorder (MDD) and is a necessary diagnostic criterion for MDD, clinicians have not directed their attention beyond the mood symptoms of MDD. We aimed to multi-dimensionally assess the functional abilities of patients with MDD using a standardized scale of adaptive function reported by caregivers or parents to identify the nature and degree of functional impairment in patients with MDD. This study was conducted in 40 depressive patients aged 19 to 60 years. Patients were screened according to the DSM-IV-TR and a Hamilton Depression Rating Scale score ≥8. We administered the parent/caregiver rating form of the Korean Vineland Adaptive Behavior Scale to assess functional outcomes in the patients. Patients with MDD showed significant differences in both global and domain-specific functional abilities compared to those of the normal group (all t > −6.35, P < .05) and the patients’ premorbid IQ (all t > 4.30, P < .001). The number of episodes among clinical factors was negatively correlated with overall adaptive functioning (r = −0.32, P < .05) and expressive communication (r = −0.42, P < .01). Our present study replicates existing evidence showing impairment in both broad and various functional areas in patients with MDD, suggesting the importance of quantitatively assessing functional outcomes and acquiring information about functioning from informants other than patients.