A Comparison of Methamphetamine-Induced Psychosis and Schizophrenia: A Review of Positive, Negative, and Cognitive Symptomatology

Abstract

Methamphetamine is a potent psychostimulant that can induce psychosis among recreational and chronic users, with some users developing a persistent psychotic syndrome that shows similarities to schizophrenia. This review provides a comprehensive critique of research that has directly compared schizophrenia with acute and chronic METH psychosis, with particular focus on psychiatric and neurocognitive symptomatology. We conclude that while there is considerable overlap in the behavioral and cognitive symptoms between METH psychosis and schizophrenia, there appears to be some evidence that suggests there are divergent aspects to each condition, particularly with acute METH psychosis. Schizophrenia appears to be associated with pronounced thought disorder, negative symptoms more generally and cognitive deficits mediated by the parietal cortex, such as difficulties with selective visual attention, while visual and tactile hallucinations appear to be more prevalent in acute METH-induced psychosis. As such, acute METH psychosis may represent a distinct psychotic disorder to schizophrenia and could be clinically distinguished from a primary psychotic disorder based on the aforementioned behavioral and cognitive sequelae. Preliminary evidence, on the other hand, suggests that chronic METH psychosis may be clinically similar to that of primary psychotic disorders, particularly with respect to positive and cognitive symptomatology, although negative symptoms appear to be more pronounced in schizophrenia. Limitations of the literature and avenues for future research are also discussed.

Cognition and Related Neural Findings on Methamphetamine Use Disorder: Insights and Treatment Implications From Schizophrenia Research

“…What is clear from all the existing studies of cognition and related brain regions in meth use disorder is how much the findings overlap with corresponding studies in schizophrenia, with far more similarities compared to differences between the two disorders. This is in contrast to the many symptomatic differences between the two disorders (7,153). While we do not know the mechanisms underlying such similarities in cognitive deficits and brain dysfunction, such overlaps provide an important opportunity to consider employing existing schizophrenia therapies for people with meth use disorder.…”

“…Despite the prevalence and associated harm, PubMed indicates that research on meth is disproportionately low compared to other substance use disorders (6) and other mental disorders. We thus propose to harness existing research in schizophrenia to provide much needed insight into meth use disorder to improve and innovate its therapeutics considering the evidence for their shared psychotic symptoms and genetic vulnerability (7)(8)(9). Schizophrenia is a chronic neuropsychiatric disorder characterized by disturbances in thought, perception, and behavior (1), and it is an extensively researched field with PubMed publications per year almost doubling all of illicit substance publications per year and more than ten times the number of publications on meth (Figure 1).…”

Methamphetamine‐associated psychosis: Clinical presentation, biological basis, and treatment options

“…A recent comparative review of positive and negative symptoms and cognition in acute and chronic MAP and schizophrenia by Wearne and Cornish () summarized that despite differences being observed between chronic MAP and schizophrenia, the gross similarities between the two conditions, as well as inconsistencies related to methodology and results between studies, continue to prevent conclusive evidence of chronic MAP representing a separate primary psychiatric disorder with schizophrenia (Wearne & Cornish, ).…”

“…Recent studies have worked to elucidate mechanisms controlling the etiology of MAP and to identify specific subgroups (e.g., transient and persistent) within the MAP population itself. A recent comprehensive review by Wearne & Cornish, (2018) has provided an effective comparison of symptom profiles within MAP and between MAP and schizophrenia (Glasner-Edwards & Mooney, 2014;Grant et al, 2012;Wearne & Cornish, 2018). Nonetheless, a paucity of research on the treatment of MAP remains to be addressed.…”

Letter to the Editor—Is Chronic Methamphetamine‐Induced Psychosis A Mental Disease for the Purposes of Insanity?

“…Methamphetamine-induced psychosis, sometimes referred to as METHassociated psychosis (MAP) (5), is divided into acute and chronic variants (5). Researchers in the area of MAP tend to use the DSM-5 30-day criteria (6) to separate a drug-induced psychosis from a persistent psychotic mental illness (5,7), although there is mounting evidence suggesting that chronic MAP may be a separate mental illness, not just schizophrenia or an unspecified psychosis precipitated by methamphetamine use (5,7). Chronic MAP is quite similar to schizophrenia symptomatically (5,(7)(8)(9) and can last for up to 6 months or even much longer after cessation of drug use (5,7,8).…”