[Clinical features of recent methamphetamine abusers: comparison between smoking abusers and injection abusers].

The author studied the clinical features of recent methamphetamine (MAP) abusers in Japan by comparing two methods of MAP use: smoking and injection. Of all the methamphetamine abusers that consulted Kanagawa Prefectural Center of Psychiatry, Serigaya Hospital, between June '97 and November '98, 67 patients that the author interviewed and treated were selected to participate in this study. The subjects consisted of two groups: 31 smoking abusers and 36 injection abusers. The results clearly showed the following: 1. Injection abusers tended to abuse organic solvents in addition to MAP, and had criminal records, lower education, and alcoholic parents more often than smoking abusers. On the other hand, smoking abusers tended to abuse cannabis, and lived in an environment similar to the general population. 2. Smoking abusers could not control MAP use, and developed acute psychotic symptoms such as hallucinations and delusions more quickly than injection abusers. 3. No remarkable differences in psychotic symptoms at acute intoxication among the two groups were seen; however, injection abusers showed more auditory hallucinations at first consultation. 4. No remarkable differences in the percentage of prolonged/chronic psychosis were detected among the two groups; however, injection abusers with psychosis needed higher doses of neuroleptics. 5. The families of smoking abusers attended family seminars more than those of injection abusers; however, there were no remarkable differences in the prognosis of the addiction rehabilitation program between the two groups. Based on the results, the author proposed a new type of MAP abuser was generated when smokable MAP was introduced to Japan. Furthermore, it was found that smokable MAP is more likely to cause loss of control and acute psychosis. However, this speculation was solely based on observation and treatment of abusers who sought consultation at medical facilities, and numerous smoking abusers who have not received treatment are considered to exist.