Budney et al. 2008). Although the cannabis withdrawal syndrome is not recognized in the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV; APA, 2000), recent research has found consistent evidence for the existence of a reliable and valid withdrawal syndrome (Budney et al. 2004; Crowley, 2006; Vandrey et al. 2008; Agrawal et al. 2008; Hasin et al. 2008; Preuss et al. 2010). For instance, findings from Hasin et al. (2008) indicate that 57.7% of frequent cannabis users in a U.S. population cohort report one or more symptoms of cannabis withdrawal. The most prevalent symptoms were feeling weak/tired, hypersomnia, yawning, psychomotor retardation, anxiety, and depressed mood.
