International Journal of Methods in Psychiatric Research
Int. J. Methods Psychiatr. Res. 19(2): 110–124 (2010)
Published online 20 April 2010 in Wiley InterScience
(www.interscience.wiley.com) DOI: 10.1002/mpr.307
110 Copyright © 2010 John Wiley & Sons, Ltd
Cannabis is the most commonly used illicit drug in the Canadian general population. Over the past two decades, its use prevalence has substantially increased, with 14% of Canadian adults reporting past-year use in 2004 (Adlaf et al., 2005). Among Ontario high-school students, one in four (26%) reported past year-cannabis use in 2007 (Adlaf and Paglia-Boak, 2007). Canada was recently reported as having the highest cannabis use rate among developed countries (United Nations Offi ce on Drugs and Crime, 2007). Despite its high use rates in the general population, cannabis in Canada is governed by a rather crude policy framework, primarily defi ned by the per se criminalization of all use by way of the prohibition of simple possession of the Controlled Drugs and Substances Act (CDSA) (Fischer et al., 2003). With this approach, any cannabis use is categorically defi ned as problematic, while abstinence is the implicitly promoted ideal (Fischer et al., 2003; Strang et al., 2000).