Eating disorder portion of the vulnerability to develop eating disorders can be inherited, and there is evidence to show that there is a genetic locus that shows susceptibility for developing anorexia nervosa. About 60% of eating disorder cases are attributable to biological and genetic components. Other cases are due to external reasons or developmental problems. There are also other neurobiological factors at play tied to emotional reactivity and impulsivity that could lead to binging and purging behaviors. Epigenetics: Epigenetic mechanisms are means by which environmental effects alter gene expression via methods such as DNA methylation; these are independent of and do not
Other specified feeding or eating disorder interpersonal difficulties. CBT-E showed effectiveness in two studies (total N = 219) and well maintained over 60-week follow-up periods. CBT-E is not specific to individual types of eating disorders but is based on the concept that common mechanisms are involved in the persistence of atypical eating disorders, AN, and BN. In 1980, "DSM-III" was the first "DSM" to include a category for eating disorders that could not be classified in the categories of AN, BN, or pica. This category was called Atypical Eating Disorder. Atypical Eating Disorder was described in one sentence in the "DSM-III" and received very little attention