0408 Insomnia Severity Differences by Psilocybin, LSD, and DMT Use Status Among Young Adult Daily Cannabis Consumers in the Herbal Heart Study

Introduction Psychedelic use and interest in its therapeutic potential are rapidly increasing; yet its relationship with insomnia remains poorly understood. This study aims to estimate differences in insomnia severity by type of psychedelic consumed among a cohort of 18-to-35-year olds. Methods Data are from the Herbal Heart Study - Sleep Ancillary (N=100) cannabis consumers. Psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) was self-reported. Insomnia and sleep problems were assessed via the Insomnia Severity Index: no clinical insomnia ( < 7), subthreshold clinical insomnia (8-10), moderate-severity clinical insomnia (15-21), and severe clinical insomnia (> 22). Measures were self-reported via REDCap. Chi-square tests, Fisher’s Exact tests, and independent t-tests were conducted where appropriate. Results Among daily cannabis consumers, 55.6% reported lifetime history of psychedelics, of which 42.9% reported past-year consumption. Psilocybin was the most prevalent (50.0%), followed by LSD (29.3%) and DMT (3.5%). Overall, 33.3% met criteria for subthreshold insomnia; 3.2% for moderate severity clinical insomnia; and 1.6% for severe clinical insomnia. There were differential associations between insomnia and psychedelic types (p< 0.05). LSD: 17.7% had moderate-to-severe-clinical-insomnia vs. 0.0% of non-LSD, p=0.006); DMT: 50.0% had moderate-to-severe-clinical-insomnia vs. 3.6% of non-DMT (p= 0.004); Psilocybin: 10.3% had moderate-to-severe-clinical-insomnia vs. 0.0% of non-psilocybin (p=0.07). Sleep problems interfered with daily functioning more frequently among LSD consumers (16.6%) than non-LSD consumers (2.8%, p=0.01). There were no differences consuming cannabis for sleep (p=0.70), or demographics [age: 26.9y (SD: 4.56) vs. 27.2y (SD: 5.56), p= 0.81, sex: 60.0% vs 60.7% female, p=0.95; or ethnicity: 68.6% vs. 57.1% Hispanic/Latino, p=0.26] by psychedelic use. Conclusion LSD and DMT were associated with clinical insomnia; and LSD consumers reported greater sleep problem interference in daily functioning. Longitudinal studies are warranted to evaluate causal effects and long-term sleep outcomes. Given the high burden of insomnia in this population, understanding psychedelic-specific associations with insomnia is essential for clinical and harm-reduction guidelines. Support (if any) R01HL153467 (Vidot); T37MD008647 (Diggs); T32 DA007292 (Baral).