abuse treatment, the occurrence of cannabis withdrawal may need closer attention than previously believed. Post-hospital marijuana use predicts poor outcome of dependence on other substances, 48 and cannabis withdrawal symptoms may contribute to such poor outcome. Coverage of cannabis withdrawal symptoms in research evaluations can provide more information on this point, potentially assisting in identification of patients at risk for poor outcome due to these symptoms. Third, the study findings further support addition of cannabis withdrawal to DSM-V and ICD-11. Our analyses did not directly investigate a valid threshold, but a 3-symptom threshold would be consistent with other withdrawal categories in DSM-IV and would identify about one-third of all frequent cannabis users. Lastly, the findings suggest that an understanding of the etiology of these symptoms would be worthwhile. Such an understanding should contribute to the development of better treatments for patients with cannabis use disorders, an increasing public health problem.
