Abstract
Psychotic symptoms and syndromes are frequently experienced among individuals who use methamphetamine, with recent estimates of up to approximately 40 % of users affected. Although transient in a large proportion of users, acute symptoms can include agitation, violence, and delusions, and may require management in an inpatient psychiatric or other crisis intervention setting. In a subset of individuals, psychosis can recur and persist and may be difficult to distinguish from a primary psychotic disorder such as schizophrenia. Differential diagnosis of primary vs. substance-induced psychotic disorders among methamphetamine users is challenging; nevertheless, with careful assessment of the temporal relationship of symptoms to methamphetamine use, aided by state-of-the art psychodiagnostic assessment instruments and use of objective indicators of recent substance use (i.e., urine toxicology assays), coupled with collateral clinical data gathered from the family or others close to the individual, diagnostic accuracy can be optimized and the individual can be appropriately matched to a plan of treatment. The pharmacological treatment of acute methamphetamine-induced psychosis may include the use of antipsychotic medications as well as benzodiazepines, although symptoms may resolve without pharmacological treatment if the user is able to achieve a period of abstinence from methamphetamine. Importantly, psychosocial treatment for methamphetamine dependence has a strong evidence base and is the optimal first-line treatment approach to reducing rates of psychosis among individuals who use methamphetamines. Prevention of methamphetamine relapse is the most direct means of preventing recurrence of psychotic symptoms and syndromes. Long-term management of individuals presenting with recurrent and persistent psychosis, even in the absence of methamphetamine use, may include both behavioral treatment to prevent resumption of methamphetamine use and pharmacological treatment targeting psychotic symptoms. In addition, treatment of co-occurring psychiatric disorders including depression and anxiety is important as a means of preventing relapse to methamphetamine use, which is often triggered by associated symptoms.