The Mickey Finn defense: involuntary intoxication and insanity.

The legal context of voluntary and involuntary intoxication is delineated. The author reports a case of involuntary intoxication involving scopolamine toxic psychosis or delirium, in which he testified as a psychiatric expert witness. The specific psychological and physiological symptomatology produced by scopolamine intoxication is outlined. The forensic psychiatrist should be alert to the involuntary intoxication defense in these cases and should familiarize himself with the specific toxicity of scopolamine, in view of the significant increase in the number of incidents in which it is utilized as "knockout" drops in certain jurisdictions.