called ‘drug craving’ [see Anton, 1999], and ultimately the development of tolerance to and withdrawal from use of the drug [Schuckit, 1995]. Some studies have shown that requiring the presence of craving and withdrawal for the diagnosis of alcohol dependence leads to a better diagnostic distinction between abuse and dependence [De Bruijn et al., 2004]. In the case of cannabis dependence, recent data from large national epidemiologic samples have confirmed that cannabis withdrawal is prevalent, correlated with more symptoms of dependence, and associated with significant distress and impairment [Agrawal et al., 2008c; Hasin et al., 2008].
