Jul 26, 2022 - Health

High-potency cannabis linked to risk of psychosis

Illustration of a red cross made out of marijuana joints.
Illustration: Brendan Lynch/Axios

Frequent use of cannabis with higher levels of THC could increase the risk of psychosis, according to a Lancet Psychiatry analysis of 20 studies covering more than 119,000 patients.

Why it matters: Cannabis use has been linked to mental health diagnoses before, but the review is the first of its kind to break down the connection between potency, mental health and addiction.

What they found: The findings suggest people who use high potency cannabis are more likely to experience addiction and are more likely to experience a psychotic disorder, such as schizophrenia.

  • The authors make the case for more public health guidelines to make cannabis use safer.
  • While higher potency and more frequent use of cannabis increases risk, the authors stopped short of associating it directly with psychosis-like symptoms.

Yes, but: The studies reviewed did not use a consistent measure to evaluate what is "low" versus "high" potency for THC, and the authors rated most studies as having just poor or fair quality design.

  • The strongest evidence of links between marijuana use and psychiatric disorders is in people with a preexisting genetic or other vulnerability, per NIH.
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