The former scientific name Anorexia nervosa means "lack of appetite nervous origin" and is a severe disorder of eating behavior. Anorexia nervosa is an eating disorder that is manifested by a disturbance in the estimation of its weight, size or shape, leading to a refusal to maintain body weight over a minimum normal and / or an intense fear of gaining weight. The obsessive desire to lose weight or, equivalently, the morbid fear of gaining weight.
A predominantly female disorder
Anorexia nervosa in the strict sense is a predominantly female disorder . In nine out of ten cases, the victim is a girl. Epidemiological data are still rare in France. United States, where anorexia nervosa is the third most chronic illness in adolescent girls after obesity and asthma prevalence was 0.48% in the 15-19 age group. The lifetime prevalence is estimated at 0.5%. A possible increase in the incidence in the general population is so far not demonstrated for anorexia clinically characterized as such (and not simple dietary restrictions).
The average age of the first signs of anorexia is around 17 years, with two peaks of prevalence at the beginning and the end of adolescence . As a rule, gravity is proportional to the earliness more anorexia nervosa expressed earlier and prognosis of evolution is dark.
For two clinical forms rarer prepubertal anorexia anorexia and late data are lacking, as well as for male cases some authors report an increase after the 1980s.
What the recognized?
Anorexia recognizes a series of indices of psychological symptoms, physiological and behavioral refusal to eat normally, fleeing foods that make you fat (sugar, fat), weight obsession and line, inability or difficulty to recognize its thinness, weight less than 85% of normal weight, absence of periods (amenorrhea for at least 3 months). 's malnutrition has important physiological consequences: loss of hair, permanent sensation of cold, access fatigue and discomfort, constipation, bleeding diaeresis, hypercholesterolemia, dehydration, pericardia, decalcification and osteoporosis, voltage drop .
The evolutionary prognosis is severe, only one third of patients go to remission, while only 1/3 retain symptoms sometimes and disabling third of them progress to chronic or life-threatening complications such as suicide or malnutrition.
Anorexia nervosa has the suicide mortality rate highest of all psychiatric disorders. Sometimes anorexia persists and ends in a very serious malnutrition and the outcome is fatal (suicide, starvation or irreversible electrolyte imbalances).
The strict diet to disorder characterized
Epidemiological data invite to consider eating disorders as a continuum from normal to pathological. Thus, in the case of anorexia, many girls practicing a system of self-restraint food trivial (typically before the summer) will be (but not explained) in some anorexia nervosa: one speaks of "forms subsyndromiques ". Only a minority takes the step towards a true anorexia. Approximately 5% of women have some symptoms of anorexia nervosa without meeting all diagnostic criteria ("subsyndromiques forms").
The behavior restriction (dieting highly restrictive, intense physical exercise) are not without risk self-reinforcing, and could be input forms, so they can evolve into pathological forms organized. For France, a survey of 35,000 students in Haute-Marne showed that bodily concerns related third girls, 20% had conducted restriction and fasting without meeting the criteria of a disease determined.
A complex disorder defying simplistic explanations
Feeding behavior depends on genetic factors and individual psychological , in close interaction with environmental factors, socio-cultural and family . The eating disorder is therefore part of a multifactorial model which can hardly isolate "a" cause as decisive.
The heritability, that is to say, the weight of genetic factors is estimated at 50-70%. The frequency of anorexia nervosa is 10 times higher in first degree relatives of anorexic women compared with control subjects (reflecting the existence of familial aggregation). Genetic vulnerability factors seem to speak more largely in disorders with depressive and obsessive dimension, corresponding to mental anorexia pure restrictive type.
Associated disorders and temperaments
There is comorbidity between eating disorders and depression . According to studies, 11% to 66% of young women with eating disorders also suffer from a major depressive episode, however, the frequency is higher in patients than in bulimic anorexics. In four out of seven studies, a decrease in self-esteem precedes the onset of eating disorder.
The "perfectionism" is a personality trait common in anorexia nervosa, with a very reduced self-esteem. The limit type personalities ( borderline ) , for which the influence of the environment is prevalent, can be found more readily in mental anorexia bulimic type ( "purging type").
One study reported a prevalence of 27% of personality disorders in eating disorders, bulimic-anorexics were more likely to personality disorder (39%) than bulimics (21%) and restrictive anorexics (22 %). Anorexics often show personalities avoidant, dependent, obsessive compulsive and passive-aggressive.
Middle age: the course of adolescence
The period of adolescence is a time for girls at risk. This stage of life marked by physical maturation (appearance of a woman's body) and mental, is a key moment in the development of anorexia nervosa. Anorexics live the future more difficult than others. Their problems seem focused on body image and self-image , closely linked to age.
The role of sociocultural factors is difficult to highlight. Several studies have shown that eating disorders were more frequent in some areas where the body is idealized in the center of professional activity (dancers, models, athletes ...).
The family background
The family dynamic is heavily involved, but it is unclear whether to interpret without any argument in favor of a primary role ("the family is partially behind the eating disorder") or secondary (the "eating disorder of the girl disrupts family dynamics "). Indeed, no twin study failed to show that the factor "non-genetic vulnerability family" differed from 0. Family dynamics is still strongly altered (secondarily) by the presence of anorexia nervosa. Approach "systemic family" is one of the therapeutic approaches with the highest validity in the literature. The families of anorexics have more problems with anxiety, control, references to the ideal play a role binding, although these are not of high specificity. The role of childhood sexual abuse in the pathogenesis of eating disorders was discussed.