Examination of the diagnostic and statistical manual of mental disorders - 5th edition (DSM-5) cannabis use disorder severity indicators.

BACKGROUND: The Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition (DSM-5) introduced cannabis use disorder (CUD) severity indicators along a unidimensional spectrum. Limited research has explored how individuals compare in severity and risk for related problems (e.g., psychiatric symptoms) across CUD severity groupings. METHOD: Participants were adults with chronic cannabis use (N = 599, 57.6 % female) drawn from several studies conducted at large southeastern universities. Confirmatory factor and item response theory analyses were conducted on interviewer-assessed CUD symptoms to evaluate latent CUD construct and severity indicator validity. Multinomial regressions were used to compare severity groups on cannabis use behaviors (e.g., Marijuana Problems Scale [MPS], Marijuana Motives Measure [MMM]), psychiatric symptoms (e.g., Distress Intolerance Index [DII], Mood and Anxiety Symptom Questionnaire [MASQ]), and other substance use (e.g., Timeline Followback [TLFB]). RESULTS: DSM-5 CUD criteria demonstrated good discrimination/difficulty (>1.00) and reflected a unidimensional latent CUD construct (factor loadings = 0.439-0.779). Latent severity scores showed some overlap between individuals with adjacent severity indicators (1.34 - 31.78 % overlap). Moderate/severe CUD differed from mild/no CUD across multiple cannabis use indices, with greater comorbid problems (general distress, daily nicotine use) in severe CUD specifically. Clinically relevant differences between mild vs. no CUD were more limited. CONCLUSIONS: Findings provide support for the validity of the DSM-5 severity indicators of CUD. Results further suggest that moderate and severe CUD appear to be a better reflection of the theory-based conception of the disorder than mild CUD within adults with chronic cannabis use.