Over the past 50 years and in the context of major changes in our environment, eating disorders have evolved into a variety of forms with overlapping and distinct clinical and aetiological features, affecting people of all ages and social classes. The prevalence of eating disorders is moderately high, although most affected individuals do not present for treatment. Lengthy periods of untreated symptoms can lead to an entrenched form of illness, which is more difficult to treat.
Eating disorders are serious psychiatric disorders characterized by abnormal eating or weight-control behaviors. Disturbing attitudes towards weight, body shape, and eating play a key role in their origin and maintenance. The form of these concerns varies by gender; in men, for example, body image concerns might focus on muscularity, whereas in women, these concerns might focus more on weight loss. Obesity per se is not framed as an eating disorder. All eating disorders considerably impair physical health and disrupt psychosocial functioning. In the classification of diseases, eating disorders encompass the following six types: diagnostic categories of anorexia nervosa, bulimia nervosa, binge eating disorder, avoidant-restrictive food intake disorder, pica, and rumination disorder.
The underlying mechanisms of eating disorders are the subject of active research. Probably, interactions between genetic and environmental factors at a crucial period in development add to the complexity of modeling these disorders. The following table summarizes the current status and divides the causes into predisposing (background vulnerabilities), precipitating (the environmental context at the time of onset), and perpetuating factors (secondary aspects of the illness that cause the illness to be valued and maintained).
Eating is an important social activity and social support can provide an important scaffold for recovery. Impaired social functioning can lead to social isolation or increased social media use (such as pro-anorexia Nervosa websites), which could be harmful. Early intervention improves outcomes; therefore, rapid commencement of specialized eating disorder treatment and care rather than watchful waiting is essential. For mild or moderately severe cases, the first step is an outpatient psychological treatment involving family members in an age-appropriate manner. If the medical or psychological risk is high or there is an irresponsiveness to outpatient care, then the greater intensity of care can be provided by outreach, day, or inpatient facilities. Studies in the UK National Health Service suggest that about 20-35% of patients will need this higher level of care. There is uncertainty about the management of patients who continue to be symptomatic following these first-line treatments, although recovery remains possible for more than 60% of patients even after 20 years. Patients often request that their families and treatment teams should not give up on them. New forms of treatments are being considered for this group, but some aspects of management are controversial. Transitions between services for age, educational, or physical reasons need to be carefully managed.
The prevalence of eating disorders is moderately high, although most affected individuals do not present for treatment. Lengthy periods of untreated symptoms can lead to an entrenched form of illness, which is more difficult to treat. Advances like biomarker and target discovery are needed to allow more precise elucidation of the mechanisms that underpin these problems and to develop more targeted treatments.