The chronic methamphetamine (MAP) intoxication model of schizophrenia in animals is outlined. The idea originated from the clinical and neurochemical similarities between MAP psychosis and schizophrenia that were found during the decade immediately after World War II when MAP abuse occurred in epidemic proportions in Japan. The chronic intoxication model is produced by daily injections of a small dose of MAP into animals for several weeks or months. Behavioral studies with various species of animals from guinea pigs to monkeys produced essentially the same disorders as those observed in human abusers. Specifically, monkeys manifest psychotic behaviors, which appear to result from perceptual-cognitive disturbances, as well as enduring autistic behavior disorders that resemble the defect symptoms in chronic schizophrenia. Furthermore, the psychotic behaviors were found to have a high relapse liability; they recurred readily after the readministration of the drug or under nonspecific stress conditions. The difference and relationship between the chronic MAP intoxication model and the amphetamine stereotypy (acute intoxication) model are discussed.

We devised a questionnaire for estimation of each tic, and used a two‐step investigation procedure, first by a parent questionnaire with 1,218 responses and second by a confirmatory telephone interview for 197 positive responses. The average estimated values were 11.3% for boys and 5.2% for girls. The prevalences were–blinking: 4.2%, head‐jerking: 1.6%, shrugging: 1.2%, mouth‐twitching: 0.6%, face‐distortion: 0.5%, mouth‐opening: 0%, throat‐clearing: 2.7%, sniffing: 0.6%, and vocalization: 0.2%. According to the criteria in DSM‐III‐R, 5.1% of 1,218 had TTD, 2.2% had CMVTD, and 0.5% had Tourette disorder.

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