Psychopharmacoepidemiology in Iceland: effects of regulations and new medications.

The sale of psychotropic medications in Iceland has waxed and waned during the past 20 years with approximately 5 years between peak and bottom quantities sold. Apparently, it has decreased following restrictions imposed by the public health authorities and increased again following the introduction of new drug. In order to study this further, all prescriptions for psychotropic medications to non-hospitalized inhabitants of the capital city (Reykjavík) and dispensed by pharmacists there during 1 month in 1984, 1989 and 1993 were analysed in order to estimate the 1-month prevalence of psychopharmacological use. The results support the hypothesis partly as prescriptions for tranquillizers decreased in 1989 as well as the amount of tranquillizers and hypnotics prescribed following new restrictions, whereas the prevalence odds ratio of obtaining prescriptions for hypnotics remained unchanged. The proportion of patients receiving excessive amounts of tranquillizers and/or hypnotics decreased. The prevalence of excessive use of these drugs (i.e. > 90 DDD/month) was 0.5% in 1993. In 1993 the prevalence of the use of antidepressants as well as the amount prescribed had increased substantially following the introduction of the new selective serotonin reuptake inhibitor medications. Thus, the prevalence of patients obtaining any psychotropic medication remained unchanged from 1984 to 1993.