Sleep, alcohol and alcohol abuse.

Use and abuse of alcohol is extremely common in many countries. Sometimes alcohol may be used to self-treat insomnia. However, alcohol consumption for any reason will affect an individual's sleep quality. The effects of alcohol use and abuse on sleep are complex and interactive. Anyone who consumes alcohol is likely to observe them, although the particular pattern and severity of the sleep impairment will differ with both the amount and duration of alcohol consumption. The fact that alcohol is a sedative and can induce rapid onset of sleep may contribute to its use, while the resultant disturbance of night-time sleep quality and of respiration may possibly result in post-consumptive daytime impairment. The persistent sleep disturbance that accompanies both acute and chronic alcohol abstinence syndromes may contribute to the continued craving and urge to resume drinking seen among chronic alcoholics. This review broadly examines the interaction of alcohol consumption and sleep disturbance. Beginning with a brief overview of normal sleep it examines the effects of modest acute alcohol consumption on sleep, sleepiness, night-time respiration and cognitive function; examines the sleep patterns of chronic alcoholics both while drinking and during acute and chronic alcohol withdrawal; reviews what is known of the relationship between alcohol use and night-time respiratory dysfunction; and concludes with some reflections on the implications of this information for drinking practices.