Participants provided information on sleep characteristics, alcohol use, and cannabis use during yearly evaluations. Sleep characteristics included circadian preference (such as preferred rise and sleep time), sleep quality, daytime sleepiness, timing of midsleep, and sleep duration on weekdays and weekends. Using statistical modeling, the research team tested whether each sleep characteristic measured over study years 0 to 4 predicted alcohol binge-drinking severity or cannabis use during the following year (years 1 to 5). Differences in participant age, sex, race, parental education, and previous year’s substance use were accounted for.
Several sleep-related factors − greater ‘eveningness’ (i.e. feeling more alert later in the day), more daytime sleepiness, later weekend sleep timing and shorter sleep duration on weekdays or weekends – were each found to predict more severe binge-drinking the following year when tested individually. When considering all sleep measures in context of one another, shorter sleep duration on weekends emerged as the predominant sleep predictor of future binge-drinking severity, with one hour less weekend sleep translating to a 19% increased risk for more severe binge-drinking the following year. Greater eveningness was the only sleep-related factor that predicted a greater likelihood of cannabis use.
While sleep characteristics are interrelated, short weekend sleep duration may be particularly indicative of an overall pattern of sleep problems. In adolescence, a tendency for later sleep is mismatched with early school start times, resulting in insufficient sleep on school nights and a need for catch-up sleep at weekends. It may be that this pattern of poor sleep, with a failure to achieve sufficient catch-up sleep on weekends, is associated with elevated risk for binge drinking. Another interpretation is that those who regularly prioritize other weekend activities over getting sufficient sleep may be the same individuals who engage in risky drinking. Other social or environmental barriers to sleep (e.g., lack of parental supervision, noise in the house or neighborhood) could also be important contributors.
Novel exploratory analyses suggested distinct patterns of sleep/substance use relationships by developmental stage. Associations between sleep characteristics and next year’s binge-drinking severity and cannabis use were stronger among participants in middle or high school than in those who had finished high school. This may again reflect the impact of early school start times on participants’ sleep schedules, compared with the potentially more flexible sleep schedules enjoyed by those in college or employment.
Overall, the research underscores a need for greater attention to sleep characteristics as potential risk factors for substance use in youth. The findings may inform new avenues to prevention and intervention, such as policy-level changes to delay school start times.
Self-reported sleep and circadian characteristics predict alcohol and cannabis use: A longitudinal analysis of the National Consortium on Alcohol and Neurodevelopment in Adolescence study. B. P. Hasler, J. L. Graves, M. L. Wallace, S. Claudatos, P. L. Franzen, K. B. Nooner, S. A. Brown, S. F. Tapert, F. C. Baker, D. B. Clark (pages xxx)
ACER-21-5039.R2