Objectives: Alexithymia, which is the inability to recognise and describe one's own emotions, is a transdiagnostic feature across eating disorders (EDs) and it has been associated with prolonged stress exposure. Therefore, we evaluated whether alexithymia was associated with hypothalamus-pituitary-adrenal (HPA) axis functioning, the main endogenous stress response system, in patients with anorexia nervosa (AN) or bulimia nervosa (BN).
Methods: 26 women with AN and 26 with BN participated in the study. Alexithymia was evaluated by the Toronto Alexithymia Scale-20 and eating-related psychopathology was measured by the Eating Disorder Inventory-2. The activity of the HPA axis was assessed by measuring the salivary cortisol awakening response (CAR).
Results: The prevalence of alexithymia did not differ significantly between the two diagnostic groups. Alexithymia was associated with more severe eating-related psychopathology in AN women but not in BN women. A significant reduction in the magnitude of CAR occurred in alexithymic patients with BN compared to non-alexithymic patients, but not in alexithymic women with AN.
Conclusions: These results confirm the presence of a more severe specific psychopathology in alexithymic individuals with AN and show, for the first time, an association between alexithymia and a dampened basal activity of the HPA axis in BN.
Keywords: Alexithymia; anorexia nervosa; bulimia nervosa; cortisol awakening response; eating disorders.