Abstract: The present article investigated clinical symptoms and their longitudinal clinical course following pharmacological treatment in 32 female incarcerated patients suffering from methamphetamine (METH) psychosis who were referred to psychiatric consultation. The length of METH-abuse periods of the patients ranged from 2 to 31 years. A total of 31 patients suffered from psychosis at abstinence after 5–31 months from the self-injection of METH. Nine of these 31 patients experienced episodes of psychotic relapse. The following symptoms were observed: auditory hallucination (29 cases), delusion of persecution (29 cases), thought broadcasting (24 cases), visual hallucination (22 cases), depressive mood (29 cases), and suicidal idea (22 cases). Patients exhibited symptoms of psychosis and depression, which persisted for more than several months despite commencement of administration of antipsychotics and antidepressants. There were significant correlations among length of periods required for improvement in total Brief Psychiatric Rating Scale (BPRS) scores, and BPRS subscale scores representing positive symptoms and depression/anxiety dimensions. Three groups of patients, according to severity of positive and depressive/anxiety symptoms, showed apparent differences in prognoses during pharmacological treatment. Average degree of extrapyramidal symptoms significantly correlated with average daily dose of antipsychotics and length-of-treatment period required for improvement in BPRS subscale scores representing positive symptom dimension. These results suggest that both psychotic and affective symptoms are involved in therapeutic response and prognosis of METH psychosis.