(HealthDay News) — The risk of psychotic experiences is increased with cannabis use during adolescence, according to a study published online Jan. 17 in JAMA Psychiatry.
Hannah J. Jones, Ph.D., from the University of Bristol in the United Kingdom, and colleagues used data from the Avon Longitudinal Study of Parents and Children to examine the association of cigarette and cannabis use with preceding and subsequent psychotic experiences. Associations between longitudinal classes of substance use and psychotic experiences at age 18 were assessed for 5,300 participants with at least three measures of cigarette and cannabis use from ages 14 to 19 years.
The researchers found strong evidence that early-onset cigarette-only use, early-onset cannabis use, and late-onset cannabis use were correlated with increased psychotic experiences compared with nonuse before adjustment for a range of potential confounders. The association for early-onset cigarette-only use was attenuated substantially after adjustment for confounders (unadjusted odds ratio, 3.03 [95 percent confidence interval, 1.13 to 8.14]; adjusted odds ratio, 1.78 [95 percent confidence interval, 0.54 to 5.88]); for early-onset cannabis use and late-onset cannabis use, the correlations remained consistent (adjusted odds ratios, 3.7 [95 percent confidence interval, 1.66 to 8.25] and 2.97 [95 percent confidence interval, 1.63 to 5.4], respectively).
“Our findings indicate that while individuals who use cannabis or cigarettes during adolescence have an increased risk of subsequent psychotic experiences, epidemiological evidence is substantively more robust for cannabis use than it is for tobacco use,” the authors write.