No drug directly causes schizophrenia—but certain substances, especially cannabis (marijuana), can significantly increase the risk of developing schizophrenia in people who are already vulnerable.
Cannabis and Psychosis Risk
Research shows that high-potency cannabis, particularly products rich in THC (tetrahydrocannabinol), is the drug most strongly linked to triggering psychotic disorders like schizophrenia. Regular use—especially starting in adolescence—can:
- Double the risk of developing schizophrenia
- Bring on symptoms earlier in those genetically predisposed
- Worsen outcomes in people already diagnosed
The risk is highest with daily use of high-THC strains (like “skunk” or concentrates). In contrast, CBD (another cannabis compound) may have protective effects—but most recreational products are THC-dominant.
Other Drugs That May Trigger Psychosis
- Amphetamines and methamphetamine: Can cause drug-induced psychosis that mimics schizophrenia, sometimes persisting long after use stops.
- Cocaine and LSD: May trigger temporary psychosis, but evidence for causing lasting schizophrenia is weaker.
- Synthetic cannabinoids (“spice”): Highly unpredictable and linked to severe, sudden psychosis.
Important Clarification
Schizophrenia is a complex brain disorder caused by genetics, brain development, and environment—not drugs alone. However, substance use (especially cannabis in teens) can act as a trigger in those already at risk.
Avoiding high-THC cannabis, particularly during adolescence, is one of the most evidence-based ways to reduce schizophrenia risk in vulnerable individuals.
If you or someone you know has a family history of schizophrenia, avoiding psychoactive drugs—especially potent cannabis—is a key preventive step.