PERIOD PREVALENCE RATES OF SPECIFIC MENTAL-DISORDERS IN AN ICELANDIC COHORT

This paper presents the 1-month, 6-month and 1-year prevalence rates f or mental disorders in a random sample of people born in Iceland in 19 31 and interviewed at the age of 55-57 years. The diagnoses were made according to DSM-III, on the basis of the National Institute of Mental Health's Diagnostic Interview Schedule (DIS) used by trained lay inte rviewers. The period prevalence rates were found to be similar to thos e obtained by other studies using the DIS as a survey instrument. The highest rates were among the widowed, separated or divorced. The 1-yea r symtom-free rates were high for alcohol abuse and alcohol dependence , 74% and 71%, respectively. For depressive disorders, the 1-year symp tom-free rate was only 50% and for the anxiety disorders, 50%-65%. The most common psychiatric disorders had a chronic course.