The Cannabis Withdrawal Scale development: Patterns and predictors of cannabis withdrawal and distress

Background: Rates of treatment seeking for cannabis are increasing, and relapse is common. Management of cannabis withdrawal is an important intervention point. No psychometrically sound measure for cannabis withdrawal exists, and as a result treatment developments cannot be optimally targeted. The aim is to develop and test the psychometrics of the Cannabis Withdrawal Scale and use it to explore predictors of cannabis withdrawal. Methods: A volunteer sample of 49 dependent cannabis users provided daily scores on the Cannabis Withdrawal Scale during a baseline week and 2 weeks of abstinence. Results: Internal reliability (Cronbach's alpha = 0.91), test-retest stability (average intra-class correlation = 0.95) and content validity analysis show that the Cannabis Withdrawal Scale has excellent psychometric properties. Nightmares and/or strange dreams was the most valid item (Wald chi(2) = 105.6. P < 0.0001), but caused relatively little associated distress (Wald chi(2) = 25.11, P = 0.03). Angry outbursts were considered intense (Wald chi(2) = 73.69, P < 0.0001) and caused much associated distress (Wald chi(2) = 45.54, P < 0.0001). Trouble getting to sleep was also an intense withdrawal symptom (Wald chi(2) = 42.31, P < 0.0001) and caused significant associated distress (Wald chi(2) = 47.76, P < 0.0001). Scores on the Severity of Dependence Scale predicted cannabis withdrawal. Conclusions: The Cannabis Withdrawal Scale can be used as a diagnostic instrument in clinical and research settings where regular monitoring of withdrawal symptoms is required. (C) 2011 Elsevier Ireland Ltd. All rights reserved.