Subjective memory and concentration deficits in medication-free, non-elderly Asians with major depressive disorder: prevalence and their correlates

BACKGROUND: Subjective cognitive impairment (SCI) in major depressive disorder (MDD) is prevalent and correlated with disability. This study aimed to examine the prevalence rates and correlates of subjective memory deficit (SMD) and subjective concentration deficit (SCD) in medication-free, non-elderly Asians with MDD.
METHODS: The SMD and SCD were assessed by using two items of the Symptom Checklist-90-Revised (SCL-90-R). Other measurements of interest included the Montgomery-Asberg Depression Rating Scale (MADRS), the Fatigue Severity Scale (FSS), the Sheehan Disability Scale (SDS), and the Short Form Health Survey (SF-36). Adjusted odds ratios with 95% confidence intervals were calculated.
RESULTS: Of 515 participants from China, Korea, Malaysia, Singapore, Taiwan, and Thailand, 347 (67.4%) and 377 (73.2%) had SMD and SCD, respectively. In total, 420 participants (81.6%) had SMD alone, SCD alone, and both deficits. Severe depression and poor mental health were significant correlates of SMD. Severe depression, clinically significant disability, poor physical health, and poor mental health were significantly independent correlates of SCD. Compared with young adults (18-34 years), older adults aged 50-65 years had a significantly lower risk of SCD (OR=.33, 95% CI: .19-.57).
LIMITATIONS: Only two SCL-90-R items were used to assess the SMD and SCD. The exclusion of MDD patients treated with psychotropic medications eliminated many patients commonly seen in typical clinic settings.
CONCLUSION: SMD and SCD are prevalent in medication-free, non-elderly Asians with MDD. Both deficits are correlated with depression and mental health status. The independent correlation between SCD and disability underscores the crucial role of SCI in MDD.
KEYWORDS: Asian; Cognitive impairment; Depressive disorders; SCL-90-R; Subjective