The Perfect Storm - A Bio-Psycho-Social Risk Model for Developing and Maintaining Eating Disorders

The eating disorders (EDs), anorexia nervosa (AN), and bulimia nervosa (BN) are severe psychiatric disorders of unknown etiology. EDs usually begin during adolescence and occur most commonly in females (American Psychiatric Association, 2013). The diagnostic criteria for AN include restriction of energy intake leading to significantly low body weight, intense fear of gaining weight, or persistent behaviors that interfere with weight gain, and disturbance in the way one's body weight, or shape is experienced (American Psychiatric Association, 2013). A restricting type (AN-R), marked by food restriction and commonly over-exercising, has been distinguished from a binge-eating/purging type (AN-B/P), where afflicted individuals eat large amounts of food in a relatively short period of time (" binge eating "), or engage in behaviors to counteract weight gain, such as self-induced vomiting or use of laxatives, or diuretics (" purging "). BN individuals are usually at normal weight, and engage in recurrent binge eating and purging behavior at least once a week for at least 3 months. A new diagnosis, " binge eating disorder " (BED) is part of the ED diagnostic categories in DSM-5. BED is associated with regular binge eating episodes without compensatory mechanisms. Individuals with ED symptoms that do not meet full criteria for AN or BN were classified as ED not otherwise specified (NOS) in the past but now fall into the categories of " other specified feeding or eating disorders (OSFED) " or " unspecified feeding or eating disorder (UFED; American Psychiatric Association, 2013). " A variety of risk factors have been identified in the past that could predispose an individual to developing an ED, as most recently and extensively reviewed by Culbert et al. (2015). Sociocultural expectations of thinness are a risk factor for all EDs (Keel and Forney, 2013); with respect to personality traits, negative emotionality, perfectionism, and negative urgency (tendency to engage in rash action when distressed) have been associated with ED development (Racine et al., 2013; Boone et al., 2014); there is evidence that the brain neurotransmitters serotonin and dopamine are associated with AN and BN, altered gene expression (epigenetics) also appears to be part of the group of risk factors for AN and BN, and increased hormone release during puberty and its effect on reward processing could contribute to the typical age of onset during adolescence. What has received little attention in the literature is how biological factors per-se not only could predispose an …