Exposure therapy for anorexia nervosa
AN has the highest rate of mortality amongst psychiatric disorders. About 25 % of patients develop a severe and enduring form of the illness, which becomes resistant to treatment due to the neuroprogressive changes associated with prolonged starvation. The ET4AN (New technologies to support eating in anorexia nervosa: A neuroimaging study) project recruited 16 patients and 21 healthy controls and developed and delivered 12 sessions of gradual and guided exposure-based therapy over a 3-month period. Programme effects were established measuring body mass index (BMI) and using self-reports to assess eating disorder symptoms, mood symptoms, rituals and disturbing thoughts around food. A brain scan measured brain activations in response to the visual presentation of images of food before and after the intervention. After the intervention, patients had higher BMI and reported significantly lower levels of eating-related concern and preoccupations. Lower levels of anxiety and increased confidence to change were also found. Interestingly, the patients' neural signatures indicated plastic changes associated with the intervention. Compared to controls, they showed a pronounced reduction of activity in the precuneus, a region associated with processing of personal phobic stimuli. In parallel, there was a significant increase in neural activity in the prefrontal cortex where planning of complex actions takes place. A previous study looking at recovered AN patients indicated increased activity in the same area of the brain. Findings from the ET4AN project indicate there is hope of reducing high levels of anxiety induced by exposure to food stimuli and inducing clinical changes in associated brain activity. The research group is currently investigating ways of disseminating details of this intervention globally to train health professionals and carers as well as peer mentors. The results will be used in the future to plan a larger randomised controlled study testing this therapeutic programme.
Keywords
Exposure therapy, anorexia nervosa, food-related anxiety, starvation, neuroimaging