A subset of individuals who chronically abuse MA develops severe recurrent psychotic symptoms, commonly termed MA psychosis. These symptoms are often associated with high levels of psychiatric hospitalization and serious social dysfunction (Leamon et al., 2002; Chen et al., 2003). Several studies have examined the prevalence of MA psychosis and one study reported a lifetime prevalence of 27% for psychotic disorder diagnoses (all substance-induced) based on the SCID (Shoptaw et al., 2003). Another study of Australian MA users reported that 23% of their sample had symptoms of psychosis in the previous year, as measured by the Brief Psychiatric Rating Scale (McKetin et al., 2006). When subjects who had a history of non-drug-induced psychotic disorder were excluded, the past year prevalence was 18%. In a another MTP follow-up study, Glasner-Edwards et al. reported that 12.7% of the sample met criteria for a lifetime psychotic disorder (Glasner-Edwards et al., 2010).
