(PS1-27) Exploration of Sleep Characteristics Between Lifetime Mono- and Poly-substance Dependence and Addiction in Current Active Illicit Drug Users

A bidirectional relationship between sleep and substance use exists with all aspects of substance use, including addiction, chemical withdrawal, long-term abstinence, and/or maintenance. Neurocircuitry associated with reward functioning may be related to sleep regulation, which may explain this relationship. However, the connection is further complicated in poly-substance use, as driving motivational factors may confound this relationship. Investigation into the nuance of the relation between mono- and poly-substance use could inform the implementation of sleep treatments in substance use interventions. In this project, we sought to identify differences in sleep duration and sleep quality between lifetime Alcohol Use disorder (AUD) only, lifetime Substance Use Disorder (SUD) only, and combined lifetime AUD and SUD in current community-dwelling illicit substance users. Of a larger substance use study, 49 participants met criteria for lifetime dependence measured via interview at baseline. Sleep data were collected via 14 days of daily sleep diaries. Descriptive statistics were used to examine sleep characteristics by substance dependence endorsement criteria. One-way ANOVAs were conducted to determine whether there were significant differences between groups. Approximately 60% of the lifetime dependence endorsing participants reported suboptimal levels of sleep duration. About 33% of U.S. adults report suboptimal hours slept per night; our sample of illicit substance users reports more than double that rate of suboptimal sleep duration, potentially highlighting the negative relationship between sleep and substance use. There were no statistically significant differences between groups on sleep duration, F(2, 44) = 0.578, p  = 0.565, nor sleep quality, F(2, 44) = 1.123, p = 0.335. The effect size calculated as eta squared was small for sleep duration (η² = 0.025) and sleep quality (η² = 0.049). Of note, about 66% (n = 29) of the sample met criteria for our poly-substance criteria, and none of the sample served as a control group with no SUD/AUD endorsement. These findings may suggest that the nuance in the sleep and substance use relationship may be dependent on current mono- versus poly-substance use as opposed to lifetime dependence criteria. Further, additional metrics of sleep not included, such as efficiency or regularity, may differ between groups. Alternatively, sleep difficulties may be more prominent throughout substance treatment, specifically during and after the withdrawal period, which is fraught with mild to severe symptoms that can be acute or chronic; 40-60% of individuals who undergo substance use treatment relapse. The frequent increase in sleep difficulties with substance use treatment, particularly insomnia, may be a contributing factor in relapse, making sleep a prime intervention target for bolstering substance use treatment. Future studies should examine more explicit indicators of mono- versus poly-substance use in multiple additional sleep characteristics in active use and treatment to inform the value of adding sleep intervention to substance use treatment, and further, tailoring sleep interventions to individuals based on deficits in sleep characteristics.