The investigation drew on data from the National Health and Resilience in Veterans Study, a rigorously conducted survey designed to reflect the demographic composition of the roughly 20 million adults who have served in the U.S. armed forces. Participants completed the Insomnia Severity Index, a validated seven-item instrument that quantifies the severity of nighttime sleep complaints—difficulty falling asleep, staying asleep, and waking too early—together with daytime impairment, distress, and dissatisfaction with sleep. Using established clinical cutoffs, the researchers classified veterans scoring 15 or higher as having clinical insomnia, while scores between 8 and 14 defined subthreshold insomnia, a state of clinically meaningful but subdiagnostic sleep disturbance. This two-tiered approach matters because much of the public health burden of poor sleep is carried not by those with formal diagnoses but by the much larger group hovering just below the diagnostic threshold.

Technically, the Insomnia Severity Index offers advantages over simpler sleep questionnaires because it captures both the objective dimensions of sleep disruption and the subjective suffering and functional impairment that accompany it. Cutoffs of 8 and 15 were validated against clinical interviews and treatment response studies, giving epidemiologists a reproducible way to stratify populations. In the new study, the proportion of veterans in the clinical range—13.6 percent—represents a relative increase of nearly 20 percent over the pre-pandemic estimate, while subthreshold insomnia rose by almost four percentage points. Combined, more than 43 percent of the veteran population now reports sleep disturbance at a level associated with impaired daytime functioning, a figure the authors describe as a substantial and growing public health concern for a population already at elevated risk for psychiatric illness and suicide.

Who is most affected? The demographic and clinical profile of veterans with insomnia is strikingly consistent across severity levels. Those with clinical and subthreshold insomnia were younger on average than their well-rested peers, more likely to belong to racial and ethnic minority groups, and disproportionately burdened by adversity. They reported greater lifetime exposure to traumatic events, higher rates of military sexual trauma, and elevated levels of homelessness, alongside a heavier load of chronic medical conditions. Each of these factors is well established in the sleep literature as a driver of hyperarousal—the physiological state of heightened vigilance that interferes with sleep initiation and maintenance—and their concentration among veterans with insomnia underscores how sleep disturbance often functions as a barometer of accumulated biological and psychosocial stress.

The strongest signal in the study, however, lies in the association between insomnia severity and mental health outcomes. After statistical adjustment for age, race and ethnicity, trauma exposure, medical burden, and other confounding characteristics, subthreshold insomnia was associated with two- to six-fold greater odds of depression, anxiety, PTSD, and suicidal ideation. Clinical insomnia carried an even heavier burden: two- to twelve-fold greater odds of these outcomes, including nearly four-fold greater odds of future suicidal intent. Suicidal intent—a construct reflecting not just passive thoughts of death but active planning or preparation—is among the most proximal predictors of suicide attempt, making the nearly four-fold elevation in this outcome particularly consequential for suicide prevention efforts within the Veterans Health Administration and beyond.

These dose-response patterns reinforce a growing body of evidence that insomnia is not merely a symptom that rides along with psychiatric illness but an active, transdiagnostic risk factor in its own right. Longitudinal and meta-analytic work has shown that insomnia predicts the onset of depression, anxiety disorders, and substance misuse in community and clinical samples, and prior research in veterans specifically has demonstrated that poor self-rated sleep quality prospectively predicts new-onset suicidal ideation over multi-year follow-up. Mechanistically, researchers point to shared pathways: chronic sleep fragmentation disrupts emotional regulation circuits in the prefrontal cortex and amygdala, impairs cognitive control, heightens inflammatory signaling, and deepens the hopelessness and social withdrawal that characterize suicidal states. Sleep, in this framing, is a modifiable upstream lever with downstream consequences for virtually the entire spectrum of psychiatric morbidity.

The temporal comparison embedded in the study adds an important epidemiological dimension. By anchoring the new prevalence estimates to a nationally representative veteran sample surveyed in 2019–2020, the researchers could quantify change across a period that included the acute and sustained disruptions of the COVID-19 pandemic. Previous prospective work in the same veteran population documented substantial new-onset and worsening insomnia symptoms during the pandemic, and global meta-analyses have confirmed elevated rates of sleep problems, particularly among women and those under pandemic-related stress. The new findings suggest that the pandemic-era surge in disturbed sleep did not simply rebound once restrictions eased; instead, a meaningful fraction of veterans appear to have crossed thresholds into clinically significant, persistent insomnia, consistent with the natural history of insomnia as a condition that, once entrenched, tends to follow a chronic and relapsing course without targeted treatment.

Importantly, effective treatment exists. Cognitive behavioral therapy for insomnia, or CBT-I, is the first-line, evidence-based intervention, producing durable improvements in sleep onset, sleep maintenance, and sleep-related distress without the dependence risks and next-day impairment associated with chronic hypnotic use. Recent randomized trials in veteran populations have strengthened the case further: brief CBT-I delivered in primary care has been tested in veterans at elevated suicide risk, and integrated protocols combining CBT-I with trauma-focused therapies such as prolonged exposure have outperformed sleep-hygiene education in veterans with comorbid PTSD. The authors argue that the sheer size of the subthreshold group—nearly a third of all veterans—creates a compelling case for early identification and intervention before sleep disturbance consolidates into full clinical insomnia and its associated psychiatric consequences.

For clinicians and health systems, the practical implications are concrete. Routine screening with the Insomnia Severity Index in veteran care settings could identify the large pool of veterans in the 8-to-14 range who are rarely captured by diagnosis-driven workflows but who carry two- to six-fold elevations in psychiatric risk. The study’s finding that insomnia clusters among younger veterans, racial and ethnic minority groups, and those with histories of military sexual trauma and homelessness also signals where outreach should be concentrated, particularly given documented disparities in access to behavioral sleep medicine. Obstructive sleep apnea, which is highly prevalent among veterans and frequently coexists with insomnia, warrants parallel evaluation so that comorbid sleep pathology is not missed. As the veteran population ages and the psychiatric and suicide burden of poor sleep becomes clearer, the authors conclude that treating insomnia—early, aggressively, and with evidence-based tools—should be regarded not as an ancillary service but as a core strategy for reducing psychiatric morbidity and suicide risk in those who have served.

Subject of Research: Prevalence and mental health burden of clinical and subthreshold insomnia in U.S. military veterans.

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

Article References: Pietrzak, R. H., Fischer, I. C., McCarthy, E., DeViva, J. C., & Na, P. J. (2026). Clinical and subthreshold insomnia in U.S. veterans: increasing prevalence and mental health burden. Journal of Clinical Sleep Medicine, 22(1), Article 167. https://doi.org/10.1007/s44470-026-00143-2

Image Credits: AI Generated

DOI: 10.1007/s44470-026-00143-2

Keywords: insomnia, veterans, sleep disorders, mental health, depression, PTSD, suicidal ideation, anxiety, Insomnia Severity Index, subthreshold insomnia, cognitive behavioral therapy, military sexual trauma