Drug-induced psychosis associated with crystalline methamphetamine.

OBJECTIVE A case of drug-induced psychosis related to crystalline methamphetamine is described, highlighting the phenomenology and relevant treatment. RESULTS A 44-year-old woman with borderline personality traits and severe drug dependence developed a protracted drug-induced psychosis related to chronic high-dose crystalline methamphetamine use. Complete resolution of symptoms occurred with antipsychotic medication and abstinence from methamphetamine. Rapid recurrence of symptoms occurred at a time of high stress associated with minimal methamphetamine use and cessation of low-dose quetiapine. Symptoms rapidly resolved with abstinence, quetiapine and reduction of stressors. CONCLUSIONS A drug-induced psychosis resembling paranoid schizophrenia can occur with repeated or high-dose use of methamphetamine. While this generally resolves rapidly with cessation of stimulant use, some cases of protracted drug-induced psychosis in vulnerable individuals have been documented. Behavioural sensitization can also occur, and neuroleptics may prevent the recurrence of further psychosis triggered by ongoing low-dose methamphetamine use.