Three distinct CUD course types were identified; persistently increasing courses are associated with specific risk factors such as male gender and externalizing disorders.
Summary
Prospective longitudinal study (n=816, age 14–30 years); three CUD course classes identified: persistently increasing, maturing out and stable-low; persistent CUD associated with later first diagnosis (η²=0,16, p<0,001) and longer CUD duration (η²=0,26, p<0,001); male gender OR=2,57 (p=0,018) and psychotic experiences (Cohen's d=0,44, p=0,016) as risk factors for the persistently increasing class.
P
PopulationAdolescents and young adults from a regionally representative sample, n=816, age at T1 mean 16,6 years (SD 1,2), 44% male, 8% non-white
I
InterventionEpidemiological longitudinal observation of Cannabis Use Disorder (CUD) across 4 assessment waves (ages 14–30 years)
O
OutcomeThree CUD trajectory classes identified: (1) persistently increasing, (2) 'maturing out' (initially increasing, then decreasing), (3) stable low; male gender (OR=2,57, p=0,018), externalizing disorders (OR=2,64, p<0,001) and psychotic experiences (d=0,44, p=0,016) discriminate the persistent from the 'maturing-out' class
Confidence in the evidence
Very lowLowModerateHigh
Moderate
The third of four GRADE levels, the effect estimate is probably reliable.
<h4>Aims</h4>To estimate cannabis use disorder (CUD) trajectory classes from ages 14 to 30 years and compare classes on clinical characteristics, risk factors and psychosocial outcomes.<h4>Design</h4>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.<h4>Setting</h4>Participants were selected randomly from nine high schools in western Oregon, USA.<h4>Participants</h4>The sample included 816 participants [age at T1 mean = 16.6, standard deviation (SD) = 1.2; 44% male; 8% non-white].<h4>Measurements</h4>Participants completed diagnostic interviews, Child Trauma Questionnaire, Social Adjustment Scale and items adapted from the Wisconsin Manual for Assessing Psychotic-Like Experiences.<h4>Findings</h4>There were three CUD trajectory classes (Lo-Mendell-Rubin likelihood ratio test < 0.001): (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 (η<sup>2</sup> = 0.16, P < 0.001) and greater cumulative CUD durations (η<sup>2</sup> = 0.26, P < 0.001). Male sex [odds ratio (OR) = 2.57, P = 0.018], externalizing disorders between ages 24 and 30 years (OR = 2.64, P < 0.001) and psychotic experiences during early adulthood (Cohen's d = 0.44, P = 0.016) discriminated between the persistent increasing and the maturing-out classes.<h4>Conclusions</h4>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.