BackgroundThe aims of this study were to examine the prevalence of drug use, and how morbidity, use of health services, self-evaluated health, demographic pattern and lifestyle characteristics influence drug use in a general population.MethodsThe study was carried out in the municipality of Tromsa, Norway. A sample of those aged 12–61 years was invited to the health survey, and 21 647 (75%) participated.ResultsThe proportion of drug users increased with age in both sexes (P < 0.0001); from 25% to 52% of women and from 18% to 38% of men. Drug use depended mainly on chronic diseases (odds ratio [OR] = 2.5 [women], OR = 3.5 [men]) and physical distress, especially symptoms of pain (OR = 2.3 [women], OR = 2.2 [men]). Number of visits to the doctor (OR = 2.4 [women], OR = 3.2 [men]) and attitude to own health (OR = 1.9 [women], OR = 1.7 [men]) were also significant predictors for drug use. Mental distress, lifestyle and demographic factors were of marginal importance (OR <1.3). Chronic diseases and visits to the doctor were the only predictors showing significant gender difference.ConclusionsDrug use increased with age and was twice as common in women as in men (OR = 2.0). After adjustment for differences in morbidity, visits to the doctor, and other factors the gender difference was significantly reduced (OR = 1.4). Higher drug use in women was attributed to women's higher level of physical distress (especially headache), higher numbers of visits to the doctor, and a higher proportion of reported chronic diseases (especially eczema, migraine) and depression compared with men.