Sixty three per cent of participants were diagnosed with two or more lifetime dependence diagnoses. Six percent met criteria for all five other lifetime dependence diagnoses, as well as heroin dependence. Use of more than one drug in any one session was common, with 73 per cent using two or more drugs concurrently. Cannabis was most commonly used concurrently with heroin (63.1%), followed by sedatives (41.2%), stimulants (33.2%) and cocaine (30.8%). Males were more likely than females to receive a lifetime diagnosis for cannabis, stimulant or alcohol dependence (Table 1). There were no sex differences in the prevalence of sedative, cocaine or nicotine dependence. Nicotine and cannabis dependence were particularly prevalent, with almost two thirds receiving a lifetime diagnosis for nicotine dependence and more than half for cannabis. Cocaine dependence had the lowest lifetime prevalence with just under one third of participants receiving a lifetime diagnosis.
