Bidirectional Relationships Between Daily Sleep and Alcohol Use.

Background: Prior longitudinal studies demonstrate that sleep disturbance is a risk factor for alcohol misuse. Experimental research also shows that alcohol intake negatively impacts sleep. The present study evaluated temporal bidirectional relationships between sleep and alcohol intake using intensive longitudinal methods.

Methods: 57 college students (71% female, Mage 24.1) participated in a two-week study assessing their daily sleep and alcohol use. Participants wore an actiwatch and completed daily diaries about their sleep and alcohol intake. Multi-level zero-inflated negative binomial models assessed whether prior sleep predicted next-day alcohol use. Linear multi-level models assessed whether alcohol use predicted daily sleep. All models assessed both within- (daily) and between-subject (average) effects because daily variations in sleep could influence alcohol use separately from average patterns and vice versa. Race, age, and sex were controlled in the analyses.

Results: Greater average wake after sleep onset (WASO) and sleep onset latency (SOL) and shorter daily total sleep time (TST) predicted greater next-day alcohol intake (WASO IR: 1.009; SOL IR: 1.011; TST IR: 0.998; p < .05). Higher average alcohol intake predicted increased daily WASO (B = 8.944, SE = 4.551, p < .05), TST (B = 12.717, SE = 5.877, p < .05), and decreased daily restedness (B = -0.158, SE = 0.064, p < .05).

Conclusions: These results highlight a dynamic bidirectional relationship between sleep and alcohol use. Findings suggest that average sleep and alcohol use patterns may be more meaningful to target than a single instance of poor sleep or excessive alcohol use.