a1 Department of Public Health, University of Helsinki, Finland
a2 Department of Psychiatry, Helsinki University Central Hospital, Finland
a3 Department of Epidemiology, Columbia University, USA
a4 Parnassia, The Hague, The Netherlands
a5 Department of Psychiatry, Groningen University, The Netherlands
a6 Departments of Psychiatry and Nutrition, University of North Carolina at Chapel Hill, USA
a7 Department of Mental Health and Alcohol Research, National Public Health Institute, Helsinki, Finland
a8 Academy of Finland, Center of Excellence in Complex Disease Genetics, Finland
Background Little is known about the epidemiology of bulimia nervosa outside clinical settings. We report the incidence, prevalence and outcomes of bulimia nervosa using for the first time a nationwide study design.
Method To assess the incidence and natural course and outcomes of DSM-IV bulimia nervosa among women from the general population, women (n=2881) from the 1975–79 birth cohorts of Finnish twins were screened for lifetime eating disorders using a two-stage procedure consisting of a questionnaire screen and the Structured Clinical Interview for DSM-IV (SCID). Clinical recovery was defined as 1-year abstinence from bingeing and purging combined with a body mass index (BMI) ≥19 kg/m2.
Results The lifetime prevalence of DSM-IV bulimia nervosa was 2.3%; 76% of the women suffered from its purging subtype and 24% from the non-purging subtype. The incidence rate of bulimia nervosa was 300/100000 person-years at the peak age of incidence, 16–20 years, and 150/100000 at 10–24 years. The 5-year clinical recovery rate was 55.0%. Less than a third of the cases had been detected by health-care professionals; detection did not influence outcome. After clinical recovery from bulimia nervosa, the mean levels of residual psychological symptoms gradually decreased over time but many women continued to experience significantly more body image problems and psychosomatic symptoms than never-ill women.
Conclusions Few women with bulimia nervosa are recognized in health-care settings. Symptoms of bulimia are relatively long-standing, and recovery is gradual. Many clinically recovered women experience residual psychological symptoms after attaining abstinence from bingeing and purging.
(Received November 09 2007)
(Revised May 19 2008)
(Accepted May 24 2008)
(Online publication September 08 2008)