Age of Substance Use Onset in Kermanshah Province: Results from a Large Cross-Sectional Study

The aim of this study is to determine the epidemiology of substance use in terms of age of initiation, duration of use and age of patients when they seek the treatment. This cross-sectional study was performed on drug-dependent individuals (4176 subjects), who had referred to methadone maintenance treatment (MMT) centers of Kermanshah province, western Iran, during year 2015. The information was gathered by psychologists working in substance use wards, who interviewed clients seeking treatment. Mean age of substance use initiation was 24.1 ± 8.2 year. On average, males and females became dependent on illegal drugs only after 3.6 and 2.5 year since substance use initiation, respectively. The chance of treatment failure for persons over 55 years was 2.5 (95%CI: 1.6 - 3.8) times higher than that for patients aged less than 24 years old. Generally, chance of treatment failure increased by 1.2 (1.1 to 1.3) for every one-year increase since substance use initiation. Given that the age of substance use initiation is very low in Kermanshah and it has a declining trend in Iran, and has a declining trend, increase/decrease in prevalence/age of using illegal drugs is expected unless efforts are made to change status and implement preventive programs.