The authors sought to determine the association of cannabis indicators with self-reported psychotic disorders in the U.S. general population.
Participants were from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; 2001–2002; N=43,093) and NESARC-III (2012–2013; N=36,309). Logistic regression was used to estimate standardized prevalences of past-year self-reported psychotic disorders within each survey and to evaluate the association of past-year self-reported psychotic disorders with indicators of nonmedical cannabis use (any use; frequent use [at least three times/week], daily/near-daily use, and DSM-IV cannabis use disorder) compared with those with no past-year nonmedical cannabis use. Whether the strength of associations differed between surveys was indicated by difference-in-difference tests (between-survey contrasts) and ratios of odds ratios between surveys.
Self-reported psychotic disorders were significantly more prevalent among participants with any nonmedical cannabis use than those without (2001–2002: 1.65% compared with 0.27%; 2012–2013: 1.89% compared with 0.68%). In 2001–2002, self-reported psychotic disorders were unrelated to either frequent use or daily/near-daily use. However, in 2012 − 2013, compared with nonusers, self-reported psychotic disorders were more common among participants with frequent use and those with daily/near-daily nonmedical cannabis use (2012–2013: 2.79% and 2.52%, respectively, compared with 0.68% among nonusers). Self-reported psychotic disorders were significantly more prevalent among participants with cannabis use disorder than nonusers in both surveys (2001–2002: 2.55% compared with 0.27%; 2012 − 2013: 3.38% compared with 0.68%). The strength of these associations did not change over time.
Data from the U.S. general population, especially more recent data, suggest associations between self-reported psychotic disorder and frequent nonmedical cannabis use and cannabis use disorder. Clinicians and policy makers should consider these relationships when monitoring patients and formulating programs.