Epidemiology of psychotropic medication use: comparison of sales, prescriptions and survey data in Iceland.

Public health issues, medical and socio-demographics, related to use of psychotropic medications and to increasing sale of antidepressants and hypnotics need to be explored. The aim of this study was to investigate the use of antidepressants, tranquillizers and sedatives nationally and its connection with health and demographic factors, by comparing: 1) sales data and 2) prescription data for outpatients with 3) self-reported use of a random sample of the population aged 18-75 years. In 2001, the sales of psychopharmaca was 168.8 daily defined doses (DDD)/1000/day, thereof 46.6% were antidepressants mainly for outpatients; one-third of hypnotics and tranquillizers were used for inpatients; 134.2 DDD/1000/day were filled by outpatients. Almost 20% of the respondents in the survey had used one or more of these drugs for some time during the preceding 12 months. Treatment adherence for antidepressants was 56%, lower for women than men. The probability of psychotropic drug use for mental complaints is 52% when controlled for other covariates. Any observed gender difference in the community survey is related to differences in the covariates, e.g. women are more likely to seek a doctor than men. The age effect on self-reported use in the community survey is related to hypnotics. The use of psychotropic medicaments is primarily driven by mental health complaints, but not by gender or age, except the use of hypnotics, which increases with age. The difference between self-reported use and prescriptions filled may reflect compliance problems in psychiatric treatment.