Cannabis use and sleep outcomes among National Guard and Reserve soldiers.

Kulak J.; Vest B.; Homish D.; Nakamura M.; Harrington M.; Homish G. · Psychological services · 2026

**Background & Methods** This longitudinal study examined cannabis use and sleep outcomes in 485 U.S. Army Reserve and National Guard soldiers over six waves of data collection from the Operation: Soldiers And Families Excelling Through the Years cohort. Generalized estimating equations were used to assess relationships between current cannabis use and multiple sleep outcomes measured by the Pittsburgh Sleep Quality Index, with adjustment for biological sex, age, and military service status. **Key Findings** • Current cannabis use was significantly associated with worse global sleep quality scores (aIRR = 1.01, 95% CI [1.01, 1.02]), indicating a dose-response relationship with cumulative worsening over time. • Cannabis use demonstrated particularly negative effects on specific sleep domains: increased sleep latency/difficulty falling asleep (aIRR = 1.15, 95% CI [1.02, 1.29]), increased sleep disturbances during the night (aIRR = 1.09, 95% CI [1.01, 1.18]), and substantially increased reliance on sleeping medications (aIRR = 1.40, 95% CI [1.10, 1.77]). • The association between cannabis use and poor sleep outcomes persisted across the six-wave longitudinal follow-up period, suggesting a sustained negative relationship rather than a transient effect. **Dosage & Administration** Not reported. The study examined current cannabis use without specifying frequency, quantity, route of administration (smoking, edibles, etc.), or cannabinoid concentrations. **Safety & Adverse Effects** The primary adverse effect identified was sleep disruption across multiple dimensions: prolonged time to fall asleep, increased nighttime awakenings, and increased reliance on pharmaceutical sleep aids. No other safety outcomes were systematically assessed. **Evidence Quality** This observational longitudinal study provides moderate-quality evidence with several limitations. The cross-sectional analysis cannot establish causality—cannabis use may be a consequence rather than cause of sleep problems, as military personnel may self-medicate poor sleep with cannabis. The study lacks information on cannabis quantity, frequency, and type (THC/CBD ratio). No control for confounding variables such as deployment history, PTSD, anxiety, or other medications was mentioned. The sample is limited to U.S. Army Reserve and National Guard soldiers, reducing generalizability. The relatively small effect sizes (aIRR values close to 1.0) warrant consideration of clinical significance. These findings represent Level 3 evidence (observational study) and highlight the need for controlled trials examining cannabis as a sleep intervention in military populations.

More recent cannabis research