The Role of Cannabis in the Development of Psychosis.
Level 5 - mechanism / opinion, no new human data
Narrative review of literature published over the last 10 years without formal systematic review or meta-analytic methodology.
PubMed 39224996 · doi:10.5080/u27122
What was done
Authors conducted a narrative review of PubMed literature published within the last 10 years using the search terms "cannabis use, psychosis, schizophrenia, endocannabinoid system, pathophysiology, neurobiology" to summarize epidemiological risk factors and neurobiological mechanisms linking cannabis use to psychosis.
What was found
The abstract reports no numerical data, effect sizes, or study counts. Narratively, it reports that epidemiological literature associates earlier age of cannabis initiation, heavy use, high-potency cannabis, and genetic predisposition with elevated psychosis risk. It also reports that adolescent cannabis use disrupts the endocannabinoid system, altering synaptic pruning and glutamate and dopamine neurotransmission, potentially worsening underlying endocannabinoid dysfunctions in schizophrenia.
Why it matters
This review outlines current conceptual models of how cannabis exposure during critical neurodevelopmental periods may interact with underlying neurobiology to increase psychosis vulnerability.
Limits
The abstract provides no quantitative data or risk estimates. As a narrative review, it lacks a systematic review methodology, structured inclusion and exclusion criteria, and risk-of-bias evaluation for the cited literature.