"From April 2009 until December 2009 the general population survey also included questions on problems related to cannabis use. These questions were derived from the DSM IV criteria for cannabis dependence and may be considered as a proxy measure of problem cannabis but they do not yield a clinical diagnosis of dependence. As these questions were introduced in the second quarter of 2009, the net sample was slightly lower (n=4,638 instead of 5,769), but prevalence rates of cannabis use were virtually the same (e.g. last year prevalence was 7.0% in the full sample and 7.1% in the reduced sample). Questions on problems related to cannabis use were only completed by respondents who had used cannabis at least five times in the past 12 months. Table 2.1.2 shows the percentages of cannabis users fulfilling the criteria. Almost one quarter (23%) responded positive to three or more 'symptoms', which can be indicative of problem use."


Van Laar, Margriet, et al., (2012). The Netherlands drug situation 2011: report to the EMCDDA by the Reitox National Focal Point. (Utrecht: Trimbos Institute, Netherlands Institute of Mental Health and Addiction), p. 41.