The Digester

Review finds cannabis not effective for common mental health conditions

Mar 17th 2026

The largest and most comprehensive analysis to date finds little or no benefit from cannabis-based medicines for many common mental health disorders and says routine prescribing is rarely justified.

  • A review of 54 randomized controlled trials with 2,477 participants found very little evidence that cannabinoids treat anxiety, anorexia nervosa, psychotic disorders, PTSD, or opioid use disorder.
  • No evidence supported medicinal cannabis as an effective treatment for depression.
  • Evidence was insufficient or absent for ADHD, bipolar disorder, obsessive compulsive disorder, and tobacco use disorder.
  • Some modest benefits were reported for reducing cannabis dependence, relieving Tourette syndrome symptoms, improving sleep in insomnia, and lowering autistic traits, but the evidence quality was low.
  • Researchers concluded that routine use of cannabinoids for mental health and substance use disorders is rarely justified given current evidence.
  • Experts and industry disagreed, and the UK advisory body is reviewing the consequences of legalising cannabis based products for medical use.