Scientists have produced evidence that the eating disorder anorexia nervosa is linked to disrupted brain chemistry.

They have shown a form of the disorder is associated with an alteration of the activity of serotonin – a chemical linked to mood and anxiety.

The University of Pittsburgh team hope their work could lead to the development of new drugs and psychological treatments.

The study is published in Archives of General Psychiatry.
The main symptom of anorexia nervosa is the relentless pursuit of thinness through self-starvation, driven by an obsessive fear of being fat.

There are two sub-types. One simply involves restricting food intake, the other involves periods of restrictive eating alternated with episodes of binge eating and /or purging, rather like bulimia.

The Pittsburgh team compared serotonin activity in women who had recovered from both sub-types of the disorder, with that in women who had never developed an eating disorder.

Using sophisticated brain scans, they showed significantly higher serotonin activity in several parts of the brains of women who had recovered from the bulimia-type form of the disorder.

Serotonin levels were also heightened in the group who had recovered from restricting-type anorexia, but not significantly so.

However, the highest levels in this group were found among those women who showed most signs of anxiety.

The researchers say their work suggests that persistent disruption of serotonin levels may lead to increased anxiety, which may trigger anorexia.

However, they could not rule out the possibility that serotonin levels were altered by the malnutrition associated with the disorder.