The small population of an island with very low rates of emigration and immigration creates a fairly unique situation for epidemiological research. This has set the trend for research in psychiatry as well as in other branches of medicine. A few ongoing studies are reviewed briefly.

A longitudinal study of a birth cohort of 5,395 probands has made it possible to estimate disease expectancy, incidence, and prevalence at different age levels. The probands still alive have reached the average age of 87 years. One half of the probands has been assigned a psychiatric diagnosis during their lifetime. The prevalence of mental disorders increases from 24% at the average age of 61 years to 40% at the average age of 87 years. The increase is caused mainly by a steeply rising prevalence of organic brain syndromes with advancing age and to a lesser extent by a rise in the prevalence of affective syndromes until the age of 75 years. The incidence of new depressive episodes increases markedly after the age of 60 years in contrast to the incidence of new manic episodes, which remains at the same level as it does until that age. An attempt is made to separate different depressive syndromes among the aged. The mortality of probands with mental disorders, especially those with organic brain syndromes and alcoholism, is increased in comparison with those without such disorders.

A random sample of the population aged 20-49 years in 1974 has been surveyed three times during a period of 10 years in order to study changes in alcohol consumption and alcohol abuse as well as in the prevalence of mental illness. A study of the consumption of general health services by psychiatric patients and reports on the attendances at psychiatric walk-in clinics and their affects on the general practitioners image of psychiatric services are mentioned.

In recent years there has been a great expansion in the treatment facilities for alcoholism. This has resulted in a very marked increase in the admission rates to in-patient treatment for alcohol abuse in spite of no increase in the average per capita alcohol consumption in Iceland, which is the lowest in Europe.

Finally an ongoing study of prescription for psychotropic drugs is referred to briefly.