Aims: To investigate the effect of alcohol consumption on the sleep and mood of healthy individuals in a college-based, mixed gender population.
Methods: Forty-seven individuals participated in this study, of whom 33 consumed alcohol and were included in the analysis. Sleep quality was objectively recorded using actigraphy. Subjects completed a daily sleep diary and bipolar Profile of Mood States Questionnaire, recording the subjective perception of sleep quality and waking mood respectively.
Results: Mean self-reported alcohol consumption among the drinkers was 84.6 ml ethanol/night. Mean total sleep time for those who consumed less than the mean reported intake was significantly reduced on alcohol. This reduction in sleep time was associated with increased wakefulness in the second half of the night, a truncated sleeping period and increased waking fatigue. This rebound wakefulness could not be demonstrated in those who consumed higher than the mean intake, though these individuals also reported increased waking fatigue.
Conclusion: These results add weight to the clinical evidence that ethanol should not be used as a hypnotic due to its potential to affect both the quantity and quality of sleep. The finding that total sleep time is reduced on low doses of alcohol is novel and may arise from measuring sleep in an environment other than the sleep laboratory.