There’s a strong association between illicit drug use and psychosis. Traditionally, researchers envision three possibilities:
- Drugs cause psychotic diseases
- People suffering from psychotic diseases self medicate
- Another factor increases occurrence of both drug use and psychosis
A new publication from Australia suggests the 1st relationship (drugs cause psychotic diseases). They present why drugs including marijuana/cannabis induce psychotic diseases.
The evidence is recapitulated accordingly:
- When healthy humans are administered cannabis, they exhibit temporary psychotic symptoms.
- Animals administered cannabis have altered behavioral patterns that model psychosis.
- In clinical studies of psychotic patients, patients with more serious symptoms tend to have used recreational drugs.
- Several cohort studies show illicit cannabis use is an independent risk factor for psychosis.
- Illicit drug use is statistically associated with earlier onset of psychosis.
- There is a very plausible mechanism:
Proposed mechanism by which marijuana and other illicit drugs can induce psychosis:
Abnormalities of dopamine pathways and the essential role of dopamine blockade to treatment response are some of the most consistent findings in our understanding of psychosis. [There is] a wide range of evidence linking cannabis and stimulants to dopamine pathways. This includes evidence from clinical and animal studies suggesting that genetic variations in monoamine metabolic pathways such as catechol-O-methyl transferase (COMT) may mediate vulnerability to psychosis on exposure to cannabis or amphetamines.
This recent publication provides compelling reason to believe illicit drug use, especially of cannabis (marijuana) causes psychosis. Without a doubt, other risk factors play a role in disease penetrance, but cannabis use has been independently shown to play a causal function.