Research Paper Title

Psychiatric disorders moderate the relationship between insomnia and cognitive problems in military soldiers.

Background

There has been a great deal of research on the co-morbidity of insomnia and psychiatric disorders, but much of the existing data is based on small samples and does not assess the full diagnostic criteria for each disorder. Further, the exact nature of the relationship between these conditions and their impact on cognitive problems are under-researched in military samples.

Methods

Data were collected from the All Army Study of the Army Study to Assess Risk and Resilience in Service members (unweighted N = 21, 449; weighted N = 674,335; 18-61 years; 13.5% female). Participants completed the Brief Insomnia Questionnaire to assess for insomnia disorder and a self-administered version of the Composite International Diagnostic Interview Screening Scales to assess for psychiatric disorders and cognitive problems.

Results

Military soldiers with current major depressive episode (MDE) had the highest prevalence of insomnia disorder (INS; 85.0%), followed by current generalised anxiety disorder (GAD; 82.6%) and current posttraumatic stress disorder (PTSD; 69.7%), respectively. Significant interactions were found between insomnia and psychiatric disorders; specifically, MDE, PTSD, and GAD status influenced the relationship between insomnia and memory/concentration problems.

Limitations

Cross-sectional nature of the assessment and the absence of a comprehensive neurocognitive battery.

Conclusions

Psychiatric disorders moderated the relationship between insomnia and memory/concentration problems, suggesting that psychiatric disorders contribute unique variance to cognitive problems even though they are associated with insomnia disorder. Results highlight the importance of considering both insomnia and psychiatric disorders in the diagnosis and treatment of cognitive deficits in military soldiers.

Reference

Brownlow, J.A., Klingaman, E.A., Boland, E.M., Brewster, G.S. & Gehrman, P.R. (2017) Psychiatric disorders moderate the relationship between insomnia and cognitive problems in military soldiers. Journal of Affective Disorders. 221:25-30. doi: 10.1016/j.jad.2017.06.023. Epub 2017 Jun 13.