Insomnia, not hypersomnolence, is seen in alcohol withdrawal. Delirium tremens is the most advanced stage of alcohol withdrawal and includes hallucinatory behavior associated with severe tremors and autonomic hyperactivity. The essential feature of delirium tremens is a delirium, with impaired attention and memory, disorganized thinking, disorientation, a reduced level of consciousness, perceptual disturbances and agitation that develops after recent cessation or reduction of alcohol consumption, usually within one week. Ref: Comprehensive Reviews in Toxicology: For Emergency Clinicians By Peter D. Bryson, 1996, Page 418; Kaplan & Sadock's Synopsis of Psychiatry, 10th Edition, Page 396.