DESIGN Using latent class analysis (LCA) we examined baseline cannabis withdrawal to derive symptom profiles. Then, using latent transition analysis (LTA) we examined the longitudinal course of withdrawal symptoms across the time points. Exploratory analyses examined demographic and clinical characteristics predictors of withdrawal class and transitioning to more or fewer withdrawal symptoms over time.
SETTING Medical cannabis clinic waiting rooms in Michigan, USA.
PARTICIPANTS A cohort of 527 adults with chronic pain seeking medical cannabis certification or recertification was recruited between February 2014 and June 2015. Participants were predominantly white (82%), 49% identified as male, with an average age of 45.6 years (SD=12.8).
MEASUREMENTS Baseline, 12-month, and 24-month assessments of withdrawal symptoms using the Marijuana Withdrawal Checklist-Revised.
FINDINGS A three-class LCA model including a mild (41%), moderate (34%), and severe (25%) symptom class parsimoniously represented withdrawal symptoms experienced by people using medical cannabis. Stability of withdrawal symptoms using a 3-class LTA at 12 and 24 months ranged from 0.58 to 0.87 with the most stability in the mild withdrawal class. Younger age predicted greater severity and worsening of withdrawal over time.
CONCLUSIONS Adults with chronic pain seeking medical cannabis certification or recertification appear to experience moderate to severe withdrawal symptoms. Withdrawal symptoms tend to be stable over a two-year period but younger age is predictive of worse symptoms and of an escalating withdrawal trajectory.