Clinical and sociodemographic correlates of severe insomnia in psychotropic drug-free, Asian outpatients with major depressive disorder

BACKGROUND: Little has been known regarding the correlates of severe insomnia in major depressive disorder (MDD). This post-hoc analysis aimed to examine the sociodemographic and clinical correlates of severe insomnia in psychotropic drug-free, Asian adult outpatients with MDD.
METHODS: Participants were psychotropic drug-free patients with MDD, aged 18-65 years. By using the Symptom Checklist-90 Items, Revised (SCL-90-R), a score of 4 (severe distress) on any one of three insomnia items was defined as severe insomnia. Other measures included the Montgomery-Asberg Depression Rating Scale (MADRS), the Fatigue Severity Scale (FSS), the nine psychopathology subscales of SCL-90-R, the Physical and Mental Component Summaries of Short Form Health Survey (SF-36 PCS and SF-36 MCS), and the Sheehan Disability Scale (SDS).
RESULTS: Of 528 participants, their mean age being 39.5 (SD=13.26) years, 64.2% were females, and 239 (45.3%) had severe insomnia. The logistic regression model revealed that low educational qualifications (less than secondary school completion), high SCL-90-R Depression scores, high SCL-90-R Anxiety scores, and low SF-36 PCS scores were independently correlated with severe insomnia (p's