Clinical and subthreshold insomnia in U.S. veterans: increasing prevalence and mental health burden.

This study examined the prevalence, correlates, and mental health burden of insomnia in a contemporary, nationally representative sample of 2,632 U.S. military veterans. Using established cutoffs on the Insomnia Severity Index (clinical insomnia, ≥ 15; subthreshold insomnia, 8-14), 13.6% of veterans met criteria for clinical insomnia and 29.7% for subthreshold insomnia, representing significant increases from the 11.4% and 26.0% observed in a nationally representative veteran sample surveyed in 2019-2020. Veterans with clinical and subthreshold insomnia were younger, more likely to belong to racial and ethnic minority groups, and reported greater trauma exposure, military sexual trauma, homelessness, and medical conditions. After adjustment for sociodemographic, trauma, and other health characteristics, subthreshold insomnia was associated with 2- to 6-fold greater odds of depression, anxiety, posttraumatic stress disorder, and suicidal ideation, whereas clinical insomnia was associated with 2- to 12-fold greater odds of these outcomes, including nearly 4-fold greater odds of future suicidal intent. These findings suggest that the burden of insomnia among U.S veterans has increased since the pre-pandemic period and underscore the importance of early identification and evidence-based treatment of insomnia to reduce psychiatric morbidity and suicide risk in this population.