Sleep quality and duration as predictors of alcohol and cannabis use motives in daily life.

Objective: Alcohol and cannabis are two of the most widely used substances in the United States, where sleep problems are also prominent. Although poor sleep is linked to substance use, little is known about how prior-night sleep contributes to next-day decisions to use substances in daily life. This study tested the impact of prior-night sleep duration and quality on momentary motives for alcohol (Aim 1) and cannabis use (Aim 2).

Methods: Adults reporting simultaneous use of alcohol and cannabis at least twice per week (N = 88; 60 % female, 85 % White, Mage = 25.22) completed 14 days of ecological momentary assessment with 5 + surveys per day. Morning surveys assessed prior-night sleep duration and quality, and all surveys assessed alcohol and cannabis use and motives for use. Multilevel models tested each aim.

Results: For Aim 1, at the within-person level, longer prior-night sleep duration was associated with greater endorsement of depression-coping motives for alcohol, but only among those reporting relatively high levels of depression at baseline. Better prior-night sleep quality was associated with greater enhancement drinking motives the next day. For Aim 2, at the within-person level, longer prior night sleep duration was associated with lower enhancement motives for cannabis use.

Conclusion: Enhancement motives for alcohol and cannabis use change as a function of day-to-day changes in sleep duration and quality. Findings highlight the idea that treatment for sleep disturbance could influence substance use motives, perhaps thereby reducing subsequent use and related consequences.