Dysregulation of the serotonin pathways has been implicated in the cause and mechanism of<unk> . There is evidence for biological, psychological, developmental, and sociocultural risk factors, but the exact cause of eating disorders is unknown. Genetic Genetic correlations of<unk>  with psychiatric and metabolic traits.<unk>  is highly heritable. Twin studies have shown a heritability rate of between 28 and 58%. First-degree relatives of those with<unk>  have roughly 12 times the risk of developing<unk> . Association studies have been performed, studying 128 different polymorphisms related to 43 genes including genes involved in regulation of eating behavior, motivation and reward mechanics, personality traits and emotion. Consistent associations have been identified for polymorphisms associated with agouti-related peptide, brain derived neurotrophic factor, catechol-o-methyl transferase, SK3 and opioid receptor delta-1. Epigenetic modifications, such as DNA methylation, may contribute to the development or maintenance of<unk> , though clinical research in this area is in its infancy. A 2019 study found a genetic relationship with mental disorders, such as schizophrenia, obsessive–compulsive disorder, anxiety disorder and depression; and metabolic functioning with a negative correlation with fat mass, type 2 diabetes and leptin. One gene that has been linked to<unk>  might be of particular interest. This gene codes for a protein called the estrogen related receptor alpha (ERRalpha). In some tissues, this gene alters the ability of estrogen and estrogen receptors to interact with DNA and change the function of cells. Since estrogen has potent effects upon appetite and feeding, any genetic abnormality in the estrogen signaling pathway could contribute to the symptoms of<unk>  and explain why<unk>  typically appears in young women just after the onset of puberty. Environmental Obstetric complications: prenatal and perinatal complications may factor into the development of<unk> , such as preterm birth, maternal anemia, diabetes mellitus, preeclampsia, placental infarction, and neonatal heart abnormalities. Neonatal complications may also have an influence on harm avoidance, one of the personality traits associated with the development of AN. Neuroendocrine dysregulation: altered signalling of peptides that facilitate communication between the gut, brain and adipose tissue, such as ghrelin, leptin, neuropeptide Y and orexin, may contribute to the pathogenesis of<unk>  by disrupting regulation of hunger and satiety. Gastrointestinal diseases: people with gastrointestinal disorders may be more at risk of developing disorders of eating practices than the general population, principally restrictive eating disturbances. An association of<unk>  with celiac disease has been found. The role that gastrointestinal symptoms play in the development of eating disorders seems rather complex. Some authors report that unresolved symptoms prior to gastrointestinal disease diagnosis may create a food aversion in these persons, causing alterations to their eating patterns. Other authors report that greater symptoms throughout their diagnosis led to greater risk. It has been documented that some people with celiac disease, irritable bowel syndrome or inflammatory bowel disease who are not conscious about the importance of strictly following their diet, choose to consume their trigger foods to promote weight loss. On the other hand, individuals with good dietary management may develop anxiety, food aversion and eating disorders because of concerns around cross contamination of their foods. Some authors suggest that medical professionals should evaluate the presence of an unrecognized celiac disease in all people with eating disorder, especially if they present any gastrointestinal symptom (such as decreased appetite, abdominal pain, bloating, distension, vomiting, diarrhea or constipation), weight loss, or growth failure; and also routinely ask celiac patients about weight or body shape concerns, dieting or vomiting for weight control, to evaluate the possible presence of eating disorders, especially in women. Studies have hypothesized the continuance of disordered eating patterns may be epiphenomena of starvation. The results of the Minnesota Starvation Experiment showed normal controls exhibit many of the behavioral patterns of AN when subjected to starvation. This may be due to the numerous changes in the neuroendocrine system, which results in a self-perpetuating cycle.<unk>  is more likely to occur in a person's pubertal years. Some explanatory hypotheses for the rising prevalence of eating disorders in adolescence are "increase of adipose tissue in girls, hormonal changes of puberty, societal expectations of increased independence and autonomy that are particularly difficult for<unk>  adolescents to meet; and increased influence of the peer group and its values." Psychological Early theories of the cause of<unk>  linked it to childhood sexual abuse or dysfunctional families; evidence is conflicting, and well-designed research is needed. The fear of food is known as sitiophobia or cibophobia, and is part of the differential diagnosis. Other psychological causes of<unk>  include low self-esteem, feeling like there is lack of control, depression, anxiety, and loneliness.<unk>  people are, in general, highly perfectionistic and most have obsessive compulsive personality traits which may facilitate sticking to a restricted diet. It has been suggested that<unk>  patients are rigid in their thought patterns, and place a high level of importance upon being thin. A risk factor for<unk>  is trauma. Although the prevalence rates vary greatly, between 37% and 100%, there appears to be a link between traumatic events and eating disorder diagnosis. Approximately 72% of individuals with<unk>  report experiencing a traumatic event prior to the onset of eating disorder symptoms, with binge-purge subtype reporting the highest rates. There are many traumatic events that may be risk factors for development of<unk> , the first identified traumatic event predicting<unk>  was childhood sexual abuse. However, other traumatic events, such as physical and emotional abuse have also been found to be risk factors. Interpersonal, as opposed to non-interpersonal trauma, has been seen as the most common type of traumatic event, which can encompass sexual, physical, and emotional abuse. Individuals who experience repeated trauma, like those who experience trauma perpetrated by a caregiver or loved one, have increased symptom severity of<unk>  and a greater prevalence of comorbid psychiatric diagnoses. In individuals with<unk> , the prevalence rates for those who also qualify for a PTSD diagnosis ranges from 4% to 52% in non-clinical samples to 10% to 47% in clinical samples. A complicated symptom profile develops when trauma and<unk>  meld; the bodily experience of the individual is changed and intrusive thoughts and sensations may be experienced. Traumatic events can lead to intrusive and obsessive thoughts, and the symptom of<unk>  that has been most closely linked to a PTSD diagnosis is increased obsessive thoughts pertaining to food. Similarly, impulsivity is linked to the purge and binge-purge subtypes of<unk> , trauma, and PTSD. Emotional trauma (e.g., invalidation, chaotic family environment in childhood) may lead to difficulty with emotions, particularly the identification of and how physical sensations contribute to the emotional response. Trauma and traumatic events can disturb an individual’s sense of self and affect their ability to thrive, especially within their bodies. When trauma is perpetrated on an individual, it can lead to feelings of not being safe within their own body; that their body is for others to use and not theirs alone. Individuals may experience a feeling of disconnection from their body after a traumatic experience, leading to a desire to distance themselves from the body. Trauma overwhelms individuals emotionally, physically, and psychologically. Both physical and sexual abuse can lead to an individual seeing their body as belonging to an “other” and not to the “self”. Individuals who feel as though they have no control over their bodies due to trauma may use food as a means of control because the choice to eat is an unmatched expression of control. By exerting control over food, individuals can choose when to eat and how much to eat. Individuals, particularly children experiencing abuse, may feel a loss of control over their life, circumstances, and their own bodies. Particularly sexual abuse, but also physical abuse, individuals may feel that the body is not a safe place and an object over which another has control. Starvation, in the case of<unk> , may also lead to reduction in the body as a sexual object, making starvation a solution. Restriction may also be a means by which the pain an individual is experiencing can be communicated. Sociological<unk>  has been increasingly diagnosed since 1950; the increase has been linked to vulnerability and internalization of body ideals. People in professions where there is a particular social pressure to be thin (such as models and dancers) were more likely to develop<unk> , and those with<unk>  have much higher contact with cultural sources that promote weight loss. This trend can also be observed for people who partake in certain sports, such as jockeys and wrestlers. There is a higher incidence and prevalence of<unk>  in sports with an emphasis on aesthetics, where low body fat is advantageous, and sports in which one has to make weight for competition. Family group dynamics can play a role in the cause of<unk>  including negative expressed emotion in overprotective families where blame is frequently experienced among its members. When there is a constant pressure from people to be thin, teasing and bullying can cause low self-esteem and
Anorexia nervosa
Substance use disorder
Bulimia nervosa
Orthorexia nervosa
Body dysmorphic disorder
Binge eating disorder
Inflammatory bowel disease
Night eating syndrome