AIMS:
To estimate cannabis use disorder (CUD) trajectory classes from ages 14 through 30 and compare classes on clinical characteristics, risk factors, and psychosocial outcomes.
DESIGN:
Four waves (T1 -T4 ) of data from an epidemiological study of psychopathology among a regionally representative sample. Trajectory classes described risk for CUD as a function of age. The number of classes was determined by model fit.
SETTING:
Participants were randomly selected from nine high schools in western Oregon, U.S.A.
PARTICIPANTS:
The sample included 816 participants (age at T1 M = 16.6, SD = 1.2; 56% female; 92% White).
MEASUREMENTS:
Participants completed diagnostic interviews, Child Trauma Questionnaire, Social Adjustment Scale, and items adapted from the Wisconsin Manual for Assessing Psychotic-Like Experiences.
FINDINGS:
There were three CUD trajectory classes (Lo-Mendell-Rubin likelihood ratio test < .001): (1) persistent increasing risk; (2) maturing out, with increasing risk then decreasing risk; and (3) stable low risk. The persistent increasing class had later initial CUD onsets (η2 = .16, p < .001) and greater cumulative CUD durations (η2 = .26, p < .001). Male sex (odds ratio [OR] = 2.57, p = .018), externalizing disorders between ages 24 and 30 (OR = 2.64, p < .001), and psychotic experiences during early adulthood (Cohen’s d = 0.44, p = .016) discriminated between the persistent increasing and the maturing out classes.
CONCLUSIONS:
Evidence suggests three distinguishable types of trajectory for development of cannabis use disorder starting in early teens: (1) persistent increasing risk; (2) maturing out, with increasing risk then decreasing risk; and (3) stable low risk. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.