Table 1.

Study characteristics

Author (year)	Country	Scale	Assessment	Mode	Subjects	Sampling (response rate)
General population samples
Steiner et al. (2008)	Germany	SDS	Dependence	Questionnaire and telephone interview	456 adult cannabis users from population survey	Probabilistic population sample (45%, total sample)
Martin et al. (2006)	Australia	SDS	Dependence	Interview	100 adolescent cannabis users	Convenience sample
Kedzior et al. (2006)	Australia	SDS	Dependence	Interview	69 adult study participants (healthy and schizophrenia patients)	Convenience sample
Kedzior et al. (2007)	Australia	SDS	Dependence	Questionnaire	50 adult study participants (cannabis users)	Convenience sample
Okulicz-Kozaryn (2007)	Poland	PUM	Dependence	Questionnaire and interview	1277 adolescent cannabis users	Snowball sample
Legleye et al. (2007)	France	CAST	Social and health problems	Questionnaire	123 cannabis users from school survey	Non-probabilistic school sample (85%, total sample)
Annaheim et al. (2008)	Switzerland	CUDIT	Chronic, acute and social problems, Motivation	Telephone interview	593 adolescent cannabis users from population survey	Probabilistic population sample (61.6%, total sample)
Specific user samples
Swift, Hall et al. (1998)	Australia	SDS	Dependence	Interview	143 long-term cannabis users	Snowball sample
Swift, Copeland & Hall (1998)	Australia	SDS	Dependence	Questionnaire and interview	200 long-term cannabis users	Convenience sample
Hides et al. (2007)	Australia	SDS	Dependence	Interview	153 in-patients with schizophrenia	Convenience sample
Ferri et al. (2000)	Brazil	SDS	Dependence	Interviewer-administered questionnaire	347 regular users of cocaine	Convenience sample
Adamson & Sellman (2003)	New Zealand	CUDIT	Dependence	Questionnaire and interview	53 out-patients with alcohol dependence (cannabis users)	Convenience sample