Novel Insights on Cannabis and Psychosis

July 28, 2020 Brian Miller, MD, PhD, MPH

There is evidence in both patients with psychotic disorders and the general population that cannabis use is associated with adverse effects of psychopathology and cognition

Substance use comorbidity in schizophrenia has been described as “the rule rather than the exception.”¹ The large Epidemiological Catchment Area study estimated that 47% of patients with schizophrenia also had a lifetime comorbid diagnosis of a substance use disorder.² Substance use comorbidity is also often deleterious to the course of schizophrenia, including potential contributions to medication non-adherence and illness relapse.¹ Cannabis (marijuana) is one of the most commonly used substances by patients with schizophrenia.

Cannabis use and risk of psychosis

Moore and colleagues⁹ … found that individuals who had used cannabis had a significant, 1.4-fold increased risk of any psychotic outcomes, independent of potential confounding and transient intoxication effects. Findings also provided evidence for a dose-response effect, with even greater, 2.1-fold risk in individuals who used cannabis most frequently.

More recently, Marconi and colleagues¹⁰ performed a meta-analysis of 10 studies, including 66,810 individuals, that investigated the association between the degree of cannabis consumption and risk of psychosis. In all individual studies, higher levels of cannabis use were associated with increased risk of psychosis. They also found evidence for a dose-response relationship, with a 2-fold increase in risk for the average cannabis user, and a 4-fold increase in risk for the heaviest users, compared with non-users.

For complete research go to (Psychiatric Times)

Also see ALL Young Cannabis Users At Risk!