A study from France's Inserm, Paris Descartes University and Sainte Anne Hospital suggests that anorexia nervosa may be linked to the pleasure of losing weight rather than the fear of gaining weight.
In a recent news release, Inserm researchers suggest that "patients felt pleasure at becoming thin rather than fear of becoming fat," an idea that contrasts with current hypotheses. In fact, the three international criteria for diagnosing the eating disorder, often associated with psychological distress, are restricted food intake leading to weight loss, distorted perception of weight and body, and fear of being fat.
To avoid being influenced by the subjective discourse of patients suffering from disease, the researchers used a "skin conductance test" to measure the rate of perspiration on their skin when exposed to various images. The emotion caused by seeing certain images leads to a rapid and automatic increase in perspiration, which can be measured objectively.
The researchers showed pictures of people with different body weights (thin, healthy, overweight) to 70 female patients consulting doctors at the Clinic for Mental and Brain Diseases (CMME) at Sainte Anne Hospital in Paris.
The results were clear. Seeing pictures of thin bodies provoked a positive emotional reaction in patients suffering from anorexia nervosa, while no particular reaction was noted in healthy subjects. The scientists explain the increase in perspiration when viewing images of thin bodies by the presence of a specific form (allele) of a gene linked with the anorexia nervosa. The disease is, in fact, partly genetic.
Showing the 70 patients images of people of healthy weights or overweight people provoked more or less the same reaction among anorexia sufferers and healthy subjects.
The discovery unveils a different approach for future work in the field of anorexia nervosa, with research oriented on reward systems rather than phobic avoidance.
The researchers also suggest that therapeutic approaches such as cognitive remediation and mindfulness therapy could have a beneficial effect on the disease.