“…However, they fail to distinguish between methamphetamine-induced psychosis and schizophrenia on the remaining symptoms of schizophrenia (Hides et al, 2015;Medhus et al, 2013;Srisurapanont et al, 2003Srisurapanont et al, , 2011, disorganized speech (e.g., frequent derailment or incoherence), grossly disorganized or catatonic behavior, and negative symptoms (e.g., diminished emotional expression or avolition; American Psychiatric Association, 2013). Many studies report affective symptoms in methamphetamine-induced psychosis, including depressed mood (Akiyama, 2006;Hides et al, 2015;Iwanami et al, 1994), suicidal ideation (Akiyama, 2006), mania (Hides et al, 2015) and hostility (Akiyama et al, 2011;McKetin et al, 2008), but it is not clear whether these are core symptoms in methamphetamine psychosis or contemporaneous phenomena. Srisurapanont et al (2011) found evidence of a positive syndrome (delusions, hallucinations and incoherent speech), a negative syndrome (poverty of speech, psychomotor retardation and flattened/incongruous affect) and an anxiety/depression syndrome (Srisurapanont et al, 2011), similar to that seen in people diagnosed with schizophrenia (Srisurapanont et al, 2011).…”