Anorexia nervosa is an eating disorder that results in food deprivation for several months or even years. As scientists attempt to pinpoint the mechanisms involved in the emergence of this disorder, researchers have shed light on the role of a specific neurotransmitter. A discovery that could soon lead to drug treatment.

Anorexia nervosa is, along with bulimia and binge eating disorders, eating disorders. This severe psychiatric disorder, which affects up to 4% of the population, is characterized by restriction of food intake leading to significant weight loss associated with an intense fear of gaining weight. The person suffering from anorexia nervosa has the feeling of always being overweight and seeks to lose weight by all means. It mainly affects girls (at least 80% of cases) and the peak of the onset of the disease is between 13-14 years and 16-17 years but anorexia nervosa can also appear in childhood or in childhood. 'adulthood.

 To date, there is no specific drug or pharmacological treatment to fight this disease. This is because the neural mechanisms involved in anorexia nervosa are still poorly understood. In addition, this obsession with weight loss under the influence of psycho-behavioral factors makes anorexia nervosa a psychiatric pathology requiring specific care: the treatment covers both the medical and psychological aspects. of disease. But researchers from the National Institute of Health and Medical Research (Inserm) recently showed the essential role of a neurotransmitter called acetylcholine in part of the brain, the striatum.

 "Dysfunctional mechanisms linked to habits"

The striatum is involved in the regulation of locomotor activity or the search for rewards. On the other hand, its function in the formation of our daily habits and our automatisms is less well known. The study published in the Journal of Clinical Investigation suggests the hypothesis that a decrease in acetylcholine in the striatum can lead to excessive habit formation that can lead to dietary restriction. The researchers * also found that it was possible to compensate for low acetylcholine levels by administering a drug commonly used in the treatment of Alzheimer's disease.

"This treatment has the effect of abolishing the pathological behaviors of the mice," explains the scientific team. The next step in the study was to work with researchers specializing in the care of people with eating disorders **, in order to transpose the results obtained in mice to humans. "Thanks to neuropsychological tests, clinical investigations with cohorts of patients have already identified the profiles suffering from severe anorexia nervosa affected by these dysfunctional mechanisms linked to habits. Add the researchers, who have developed a protocol based on the use of this drug.

 A way to also treat OCD

This discovery is important since there is no proven drug treatment for anorexia: this study therefore opens up a serious therapeutic target. A first pilot study is expected to start shortly and the researchers hope to see results within a year or two. Moreover, the latter conclude on the fact that beyond anorexia, "this discovery could apply to pathologies which involve the creation of habits and compulsions such as addictions or obsessive and compulsive behaviors (OCD ). It should be noted that according to Inserm, the early management of anorexia nervosa is a determining factor in recovery.

Indeed, the goals of care are to restore weight, treat psychological suffering and minimize social and relational consequences. "It is essential to involve the entourage in the care, especially the family, for minors but also for adults. », Specifies Inserm on this subject. Currently, the management and follow-up are multidisciplinary, psychological (support, behavioral and family therapies) and somatic. While drug therapy may be recommended, it is used to relieve psychiatric disorders associated with anorexia nervosa, including depressive and anxiety symptoms, or somatic complications.