Alcohol-induced sleep disorders typically occur as insomnia type.

With acute alcohol use, during the intoxication period, there is a reduction in sleep latency, increase in NREM sleep stages 2 and 3, and reduced REM sleep. Following this, there may be increased wakefulness, restless sleep, and vivid, anxiety-filled dreams during the latter period of sleep. During withdrawal, individuals experience extremely disrupted sleep continuity and increased, intense REM with extremely vivid dreams which can be part of alcohol withdrawal delirium.

With habitual alcohol use, these individuals experience sedative effects for the first half of the night and sleep continuity disruption in the second half. Chronic alcohol users may complain of fragmented sleep for months to years as well as experience slow-wave sleep deficits.