Nutritional rehabilitation in anorexia nervosa (AN) is impeded by fear of food, eating and change leading to treatment resistance. Oxytocin exerts prosocial effects on anxiolysis, fear modulation, trust and brain plasticity.

A placebo-controlled RCT examined the effects of self-administered intranasal oxytocin (IN-OT) in AN patients.

To ascertain whether single and repeated doses of IN-OT enhance treatment in AN.

Female AN patients self-administered twice daily 18IU IN-OT (n = 21) or placebo (n = 21) for 4–6 weeks during hospital treatment. Weight and BMI were measured at baseline and after treatment. The Eating Disorders Examination (EDE) was the primary outcome measure. Cognitive rigidity was compared between groups after four weeks repeated dosing. The effects of the first and last doses of IN-OT versus placebo, on salivary cortisol before a high-energy afternoon snack, were compared.

Weight gain was similar in IN-OT and placebo groups. Only the EDE eating concern subscale score was significantly lower after 4–6 weeks (mean 35 days) of IN-OT (p = 0.006). Anticipatory levels of salivary cortisol fell from baseline after the initial dose in contrast to the placebo group where levels increased. After four weeks IN-OT, salivary cortisol was significantly lower (p = 0.023) overall with little anticipatory increase compared to placebo. There were no differences in anxiety scores. Cognitive rigidity was significantly lower in the IN-OT group (p= 0.043)

Self-administered IN-OT might enhance nutritional rehabilitation in AN by reducing eating concern and cognitive rigidity. Lower salivary cortisol before a high-energy snack, suggests reduction of fear rather than anxiety.

The authors have not supplied their declaration of competing interest.