Genetic factors - Linkage analysis of genes within the genome found no loci for broad diagnostic categories of anorexia nervosa, but analysis of pedigrees of at least one pair of relatives with the restrictive type of anorexia nervosa determined grip chromosome 1r34 (Grice et al, 2002). Drive for thinness and obsession are most closely associated with anorexia nervosa, causing new genetic loci on chromosomes 1 for mixed indicator and 13 to drive for thinness (Devlin et al, 2002). Research on the relationships focused on the study of genes related to a specific neurochemical factors of eating disorders. One such candidate is NTR2A gene for serotonin 5-HT2A receptor. Gene brain-derived neurotrophic factor (BDNF) is also involved as a susceptibility gene for anorexia nervosa. This protein is involved in the regulation of feeding behavior at the level of the hypothalamus, including in the regulation of the level of serotonin , which causes a decrease in depression. Genetic vulnerability, probably lies in the predisposition to a certain type of personality , mental disorders ( mood disorder or anxiety disorder) or dysfunction of neurotransmitter systems. Therefore, genetic predisposition or vulnerability may occur in adverse conditions, such as improper diet or after emotional stress.
Biological factors - overweight and early menarche. In addition, the cause of the disease may be due to dysfunction of regulating feeding behavior of neurotransmitters , such as serotonin , dopamine , norepinephrine . Studies have demonstrated the dysfunction of all three of the above mediators in patients with eating disorders. Nutritional deficiencies - deficiency of zinc plays a role in anorexia, but not the cause of the disease. There is evidence that this may be a factor that deepens the pathology of anorexia. In 1994, a randomized placebo controlled study showed that zinc (14 mg per day) doubled the rate of increase in body weight compared with patients receiving placebo.
Family factors - more chances of eating disorders in those who have relatives or loved ones suffering from anorexia nervosa, bulimia nervosa and obesity . In the presence of a family member or relative who suffers from depression , abuse of alcohol or drugs or dependence, also increases the risk of illness.
Personal factors - the psychological risk factors are perfectionist, obsessive personality type, especially the restrictive type of anorexia nervosa. Low self-esteem, feelings of inadequacy, insecurity and inadequacy are risk factors for anorexia nervosa .
Cultural factors - these include: living in an industrialized country and the emphasis on thinness (thinness) as the main sign of feminine beauty. Stressful events such as the death of a close relative or friend, sexual or physical abuse may also be risk factors for developing an eating disorder.
The age factor - in terms of psychological domestic patopsihologicheskih school age is one of the most important conditions predispose to anorexia. Risk group is adolescence and early adulthood . In recent decades there has been declining age of manifestation of the disease.
Anthropological factors - in terms of doctor of medicine, psychophysiology Vadim Rotenberg, anorexia nervosa is associated with the search activity of man: