Mental health problems as a cause of long-term sick leave in the Norwegian workforce

There has been a growing concern about the proportion and socioeconomic consequences of work incapacity due to mental health problems. The aim of the present study was to describe the incidence and duration of different categories of mental health problems with at least two weeks of compensated absence from work in the general working population in Norway.

Cases were identified from files of the national medical insurance system, covering 90% of all employees, while census data were used for the denominators. Based on the International Classification of Primary Care, a total of 101,512 individuals with one or more long-term sick leaves (>2 weeks) due to psychological problems were identified in 1997 and 1998.

Employees absent for psychological problems accounted for 16.8% of all incidences and 31.5% of all refunded sick days. The average one-year incidence was 2.47%, and was significantly higher for women (3.53%) than for men (1.66%). The incidence increased with increasing age, and more so for women than for men. The median duration of absence for all claimants was 79 days. Approximately 25% were back to work after one month, 52% after three months, while 8.5% had not returned to work after 12 months and were transferred to other forms of compensation. The length of sick leave varied considerably with diagnostic category, age, and gender.

Mental health problems constitute a major health problem in the Norwegian workforce today. There is an urgent need for more knowledge about the effectiveness of interventions.