Risk factors for anorexia nervosa: a national cohort study.

OBJECTIVE

To identify possible risk factors for anorexia nervosa through national registers.

METHOD

The study includes the entire Swedish population of 989,871 individuals born between 1973 and 1982. Patients with anorexia nervosa were identified through the Swedish Hospital Discharge Register from November 1990 to December 1999. Information about sociodemographic, perinatal, and psychosocial variables was obtained from different national registers. Attributable risk (AR) was calculated for potential risk factors.

RESULTS

Females had the highest AR for hospital admission because of anorexia nervosa (89.2%). Another important risk factor was having parents born in northern, central, or eastern Europe (AR: 49.3%). Psychosocial risk factors also were associated with an increased risk for anorexia nervosa (AR: 7.6%), whereas perinatal complications had an AR of only 3.6%.

DISCUSSION

The most important risk factors were related to the sociocultural context of the individual, thus supporting hypotheses of a sociocultural etiology of anorexia nervosa.