Return of depressed men: changes in distribution of depression and symptom cases in Norway between 1990 and 2001

Women's elevated risk of depression compared to men is a common finding in psychiatric epidemiology. Studies conducted in the 1950s and 1970s, however, documented approximately equal prevalence of sex rates.

This study investigated changes in depression rates between 1990 and 2001 in Norway. Further, differences in severity were examined between men and women.

A study population (later to be called OsLof) was established in 1990, supplemented in 2001, and analysed as two cross-sectional datasets to compare sex and age differences in ICD-10 diagnoses and HSCL-25> or =1.75 caseness. Organic depression and the DSM-IV Major Depressive Episode were also examined in 2001.

There was no significant change in the prevalence of depression or HSCL-25 caseness from 1990 to 2001. However, a major shift in prevalence occurred over time within the 18-34 year old age category with significantly higher rates among younger men (1% to 10%) and lowered rates among younger women (10% to 4%). Among persons depressed, no significant differences were found for severity between the sexes.

A selection of healthier participants than found in the source population might have resulted in lower prevalence than real.

There was no indication of an overall increase in depression from 1990 to 2001, neither by diagnosis nor by symptom checklist scores. However, a major shift in prevalence occurred within the 18-34 year old age category with significantly higher rates among younger men and lowered rates among younger women. No sex differences existed in terms of severity of depression.