, 1999). Considering the association between cannabis use and psychiatric disorders (e.g. Degenhardt et al., 2012, Lev-Ran et al., 2013 and Zammit et al., 2002), there are

reasons to believe that cannabis use would be associated with DP. In this study, we will therefor make use of a cohort study spanning over nearly 40 years to investigate (1) if there is an association between cannabis use in adolescence and future DP and (2) if possible associations persist after adjustment for a number of potential covariates. The study cohort, comprising 49,321 Swedish men has been described in detail elsewhere (Andréasson et al., 1987). In short, our study is a register follow-up to the cohort study including all Swedish men born in 1949–1951 selleck chemicals llc who were conscripted to compulsory military service in 1969–1970 (aged 18–20 years). The cohort covers approximately 97.7% of the Swedish male population at that time. Those not participating were exempted due to severe handicaps or congenital disorders. At time for conscription all men answered two questionnaires, one focused on alcohol consumption, tobacco

and illicit drug use, and the other was based on questions on family and social click here background, school performance, psychological factors, behavior and adjustment and self-rated health. In addition to this, they went through physical and psychological tests and a physician diagnosed physical and mental disorders according to the Swedish

version of the International Classification of Disease (ICD) 8th revision (ICD-8). Those with a psychiatric disorder were also examined by a psychiatrist. The study exposure is self-reported cannabis use at time for conscription. Questions were asked whether subjects had ever used drugs (including cannabis), which drugs had ever been used, first drug used, drug most commonly used, frequency of use and questions regarding use of specific drugs from a list with alternatives. The question about frequency of use had also fixed response alternatives; never, 1–2 times, 3–10 times (those two categories were collapsed into one; 1–10 times), 11–50 times and >50 times, that were used in our analyses. The study outcome is first time of being granted DP between 20 and 59 years of age. Data on DP was collected from the National Social Insurance Agency for the years 1971 to 1989 and from Longitudinal Register of Education and Labor Market Statistics from 1990 to 2008. DP was categorized into three groups, i.e., overall (aged 20–59), early DP (aged 20–39) and late DP (aged 40–59). A majority of all disability pensions occur during the second part of working life, i.e. after the age of 40. Based on previous studies on DP, we accounted for the following covariates: Social background including childhood socioeconomic position (SEP), i.e.