Intravenous drug abuse in young men: risk factors assessed in a longitudinal perspective.

The role of family background as well as behavioural and psychological factors as risk factors for intravenous drug abuse was analysed in a longitudinal study of 8168 Swedish men conscripted for military service in 1969-70. Information about risk factors was obtained from a survey of all Swedish conscripts. Records on intravenous drug abuse, during a followup ending in 1986, were obtained from a survey of intravenous drug abusers among persons brought to the Central police arrest in Stockholm. Strong predictors of intravenous drug abuse were contact with the police of juvenile authorities (RR = 22.3 95% CI 15.1-33.0), high alcohol consumption (RR = 9.2 95% CI 6.7-12.7) and psychiatric diagnosis at conscription (RR = 6.0 95% CI 4.5-8.1) and low social class (RR = 3.6 95% CI 2.2-5.9). In multivariate analyses, these factors and indicators of deviant behaviour still carried significantly increased relative risk for intravenous drug abuse, although several of them are interrelated. Low emotional control, nervousness, sleeping problems and other nervous problems were associated with an increased relative risk in univariate but not in multivariate analyses.