Insomnia: Sex differences and age of onset in active duty Army soldiers

The prevalence of insomnia symptoms, insomnia diagnostic status, and age of onset compared by sex is understudied within the military population. Data were examined from the All Army Study to Assess Risk and Resilience in Service members (N = 21,294; 18-61 years; 11.7% female and 87.6% male). Participants were given a self-administered version of the Composite International Diagnostic Interview Screening Scales to assess psychopathology and cognitive deficits, and the Brief Insomnia Questionnaire for insomnia disorder assessment. Participants identified the age they first experienced sleep problems for 1 month or longer as part of the self-administered questionnaire. Among this sample of Army soldiers, 22.8% met insomnia diagnostic status (22.0% of males and 28.4% of females). A binary logistic regression model revealed that insomnia diagnostic status was associated with female soldiers (OR = 1.26, P< .001, 95% CI = 1.13-1.41) compared to male soldiers, even when accounting for sociodemographic variables and mental health disorders. No significant sex differences emerged at insomnia symptom level or sleep problem age of onset. This study highlights the importance of examining insomnia by sex in active-duty populations. Results suggest that female active duty soldiers experience insomnia at a higher rate than their male counterparts, which may be driven by reports of daytime impairment. Given this information, more specific clinical recommendations on assessing and treating insomnia could be provided, especially when considering readiness for military duty.