Alcohol withdrawal syndromes in the human: comparison with animal models

Alcohol withdrawal syndromes in humans lie on a continuum of increasing severity, from the acute hangover to delirium tremens. Early mild reactions consist primarily of hyperexcitability phenomena such as tremor, insomnia, hyperreflexia and hyperventilation. In more severe degree, the same process gives rise to hallucinations and seizures. These early reactions are mimicked closely by alcohol withdrawal signs in experimental animals. Late reactions in humans are characterized by marked sympathetic nervous system overactivity, profound disorientation and hallucinations. Analogous reactions have not yet been observed clearly in other species. The problem may be one of finding appropriate techniques for detecting such changes, rather than a true species difference in their occurrence.