A comparison of eating disorder symptomatology, psychological distress and psychosocial function between early, typical and later onset anorexia nervosa.

Objective: Epidemiological studies suggest that the incidence of anorexia nervosa (AN) is increasing in younger populations, with some evidence that clinical differences occur according to age of onset (AOO), which may impact prognostic outcomes. The current study sought to compare eating disorder (ED) symptomatology, psychological distress and psychosocial function between early onset (EO), typical onset (TO) and later onset (LO) AN in a large sample of treatment-seeking patients with a diagnosis of AN.

Methods: Participants included 249 individuals with a diagnosis of AN who were assessed at an outpatient ED service. The sample was divided into three groups based on AOO; those with an AOO ≤14 years (N = 58) were termed 'EO-AN', those with an AOO between 15 and 18 years (N = 113) were termed 'TO-AN' and those with an AOO of > 18 years (N = 78) were termed 'LO-AN'. Comparisons were made between AOO groups on assessments of ED symptomatology, psychological distress and psychosocial function.

Results: EO-AN patients reported a significantly longer illness duration than both TO-AN and LO-AN groups. After controlling for effect of illness duration, the EO-AN group demonstrated significantly higher ED symptomatology and dysmorphic concern compared to the LO-AN group. The EO-AN group demonstrated significantly decreased cognitive flexibility compared to both the TO-AN and LO-AN groups.

Discussion: These findings suggest that clinical differences do occur according to AOO in AN whereby EO-AN may represent a more severe form of illness that is not attributable to increased illness duration. Treatment strategies which specifically address patients with EO-AN may improve long term health outcomes and recovery.