Anorexics don't see health dangers because of brain abnormalities linked with a lack of insight

People who suffer from anorexia may have trouble recognising their eating disorder is endangering their health because of abnormalities in the brain regions involved in forming insight and self-reflection, scientists have said. The failure to take a step back on their behaviours mean these patients are also less likely to respond well to treatment.

Anorexia nervosa is a severe and potentially fatal eating disorder which is defined in the DSM-5 –the international reference for the definition of mental health disorders – as a condition leading to restriction of food intake and abnormally low body weight, a distorted perception of body weight and an intense fear of gaining weight.

It is known to be particularly difficult to treat because patients tend to have distorted body image, obsessive thoughts, and poor insight, which limits their adherence to treatment.

In the latest study, published in Psychological Medicine, scientists have conducted a study of structural brain connectivity to see whether these characteristics of the disorder – lack of insight in particular – were apparent in the brain.

An 'error message'

In people with anorexia, they found anomalies in the caudal anterior cingulate and the posterior cingulate – two areas which have been shown to play a role in error detection, conflict monitoring, and self-reflection.

The brain maps suggest that these two areas are poorly connected with the rest of the brain in people with anorexia compared to healthy participants. Moreover, anorexic participants with worse insight scores had the worse integration of these brain areas.

"The brains of people with anorexia nervosa who have poor insight may not generate an 'error message' when told, for example, that they are putting themselves at serious risk for death by severe restricting," explains corresponding author Dr. Alex Leow from UIC College of Medicine, "Thus, it is plausible that their brains literally don't believe that they are severely underweight and their behaviour is dangerous even when objective evidence suggests otherwise. Without insight, they are stuck."

The researchers also found that individuals with anorexia had abnormal, overlapping brain networks involved in reward and compulsive behaviours. This may explain why many anorexics get a rewarding feeling from successfully carrying out compulsive exercising and eating restrictions.

"Improving anorexics' ability to detect the mismatch between their perceptions of self and reality may be the key to helping some recover. We may be able to teach insight to these patients using different tools or techniques including virtual or augmented reality technologies," Leow concludes.