Researchers Warn of a Growing Epidemic of Drug-Induced Psychosis | Research

The takeaway

A review argues that rising recreational use of methamphetamine and high-potency cannabis over 30 years has driven a substantial increase in drug-induced psychosis, with 25-50% of cases progressing to schizophrenia.

Policymakers evaluating cannabis legalization impacts, mental health clinicians, public health advocates.

25-50% of drug-induced psychoses progress to schizophrenia within 5 years

What the researchers found

Drug-induced psychosis from methamphetamine and cannabis has become more common over three decades. Between 25% and 50% of drug-induced psychosis cases progress to schizophrenia within five years. Cannabis potency has increased substantially, particularly in jurisdictions that have legalized it.

Why it matters

The comparison to the obesity epidemic is provocative but grounded in a real pattern: policy and market changes driving population-level health consequences that emerge gradually. The 25-50% progression rate from drug-induced psychosis to schizophrenia represents a significant clinical concern.

The numbers in context

25-50% of drug-induced psychoses progress to schizophrenia within 5 years; worldwide legal cannabis sales for 2025 estimated at $65 billion; 30-year trend of increasing drug-induced psychosis.

How the study worked

Narrative review and commentary synthesizing epidemiological evidence, policy analysis, and clinical observations on trends in drug-induced psychosis from methamphetamine and cannabis.

What this study cannot tell us

Commentary-style paper with selective evidence presentation. Does not systematically assess all available evidence. The epidemic framing may overstate the certainty of future trends. Does not account for potential benefits of legalization such as reduced criminalization.

How to read the evidence

Moderate: Draws on established epidemiological evidence but presents it through a commentary lens with selective citation rather than systematic methodology.

When this study was published

Published in 2025, reflecting current policy landscape.

The bigger picture

This paper sits within a growing body of literature connecting cannabis commercialization, rising potency, and psychosis risk. The authors frame the current moment as the beginning of a potential epidemic, analogous to predictions about obesity in the 1980s.

Questions still open

Will public education campaigns similar to anti-smoking efforts be effective for cannabis? How much of the psychosis increase is attributable to increased potency versus increased use? Are psychiatric services in legalized jurisdictions already showing strain?

Common questions

What is drug-induced psychosis?

Drug-induced psychosis is a condition where substance use triggers psychotic symptoms like hallucinations and delusions. It can occur during intoxication or withdrawal and in some cases represents the first episode of a longer-term psychotic disorder.

How does cannabis potency relate to psychosis risk?

Higher-potency cannabis products deliver more THC per dose. Research has linked high-potency cannabis use to elevated rates of psychotic experiences, and the authors note that potency has increased substantially in legalized markets.

Read the original research

The rising tide of drug-induced psychosis.

Neuropsychiatrie : Klinik, Diagnostik, Therapie und Rehabilitation : Organ der Gesellschaft Osterreichischer Nervenarzte und Psychiater

View on PubMed ↗Publisher’s paper ↗

Citation

Murray, Robin M; Paparelli, Alessandra; Di Forti, Marta; Morrison, Paul. (2025). The rising tide of drug-induced psychosis.. Neuropsychiatrie : Klinik, Diagnostik, Therapie und Rehabilitation : Organ der Gesellschaft Osterreichischer Nervenarzte und Psychiater. https://doi.org/10.1007/s40211-025-00541-7