Prevalence and long-term course of lifetime eating disorders in an adult Australian twin cohort.
OBJECTIVE
Few studies exist that have examined the spectrum and natural long-term course of eating disturbance in the community. We examine the lifetime prevalence and long-term course of anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified (EDNOS) in an adult female twin population.


METHODS
Female twins (n = 1002) from the Australian Twin Registry, aged 28-39 years, were assessed using the Eating Disorder Examination, revised to yield lifetime diagnostic information. For women with lifetime eating disorders, the assessment occurred, on average, 14.52 years (SD = 5.65) after onset of their disorder.


RESULTS
In accordance with other community studies, we found a 1.9% lifetime prevalence of AN, with an additional 2.4% who met the criteria for 'partial AN' (absence of amenorrhea). Criteria for BN were met by 2.9% of the women, an additional 2.9% of women met criteria for binge eating disorder, while 5.3% met criteria for purging disorder unaccompanied by binge eating (EDNOS-p). Eleven (7%) of the women with lifetime eating disorders had a current eating disorder. Each diagnostic group continued to be differentiated by current eating pathology from women without lifetime eating disorders. Although approximately 75% of the women had a good outcome, less than 50% of each diagnostic group was asymptomatic.


CONCLUSIONS
Eating disorders tend to improve over time often reaching subdiagnostic levels of severity, but only a minority of sufferers becomes asymptomatic. The DSM-IV diagnosis EDNOS needs to be considered in studies of the prevalence and course of eating disorders.
School of Psychology, Flinders University, Adelaide, South Australia, Australia. tracey.wade@flinders.edu.au
Tracey D
TD
Wade
Jacqueline L
JL
Bergin
Marika
M
Tiggemann
Cynthia M
CM
Bulik
Christopher G
CG
Fairburn
D000328:Adult; D017668:Age of Onset; D000856:Anorexia Nervosa / Q000175:diagnosis / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D001828:Body Image; D015992:Body Mass Index; D052018:Bulimia Nervosa / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D001068:Feeding and Eating Disorders / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015995:Prevalence; D012042:Registries; D013997:Time Factors; D014427:Twins