Socio-demographic, and psychiatric and substance use-related characteristics of the study population are presented in tables 1 and table 2. Approximately 80% of individuals with dependence on nicotine and alcohol and almost all individuals with cannabis or cocaine dependence had a lifetime diagnosis of another psychiatric disorder (Table 2). About one-third of individuals with nicotine or alcohol dependence and almost two-thirds of those with cannabis or cocaine dependence had a lifetime diagnosis of a mood, anxiety or PD. Approximately two-thirds of individuals with dependence on any of the substances assessed had a family history of substance use. Rates of early substance use onset were highest among individuals with dependence on nicotine, followed by cannabis, alcohol and cocaine.
