Clinicians diagnose an individual as having anorexia nervosa (AN) when he or she shows three basic types of symptoms: severely restricted eating, which leads the person to have an abnormally low body weight, intense and unrealistic fear of getting fat or gaining weight, and disturbed self-perception of body shape or weight. In other words, people with this eating disorder restrict their food intake, become preoccupied with gaining weight, and feel that they are already overweight even though they may be seriously underweight. DSM-IV-TR currently requires that the individual “refuse” to eat or maintain body weight. The DSM-5 authors recommend changing this to the more behaviorally oriented term “restriction.” DSM-IV-TR uses “intense fear” of gaining weight as a criterion, but DSM-5 would add the option that emphasizes behavior (“persistent behavior that interferes with weight gain”). DSM-IV-TR also includes amenorrhea (cessation of menses) as a criterion, but the DSM-5 authors suggest removing this because not all women with the disorder experience disturbed menstrual periods—or they may be pre-adolescent or post-menopausal.
Within the AD category, clinicians may classify individuals as “restricted type,” meaning that they do not engage in binge eating and “binge-eating/purging type,” which means that they do. Currently, the DSM-IV-TR categorizes individuals as one of these two types based on the symptoms that they show while they are undergoing assessment. The DSM-5 authors propose basing the subtype on behavior that an individual has shown over the past 3 months, which is consistent with the subtyping that clinicians use for binge-eating disorders.
The depletion of nutrients that occurs in people with anorexia nervosa leads them to develop a series of health changes, some of which can be life threatening. Their bones, muscles, hair, and nails become weak and brittle, they develop low blood pressure, slowed breathing and pulse, and they are lethargic, sluggish, and fatigued. Their gastrointestinal system functions abnormally and they may become infertile. Most seriously, their heart and brain suffer damage and they may experience multiple organ failure. These changes can have fatal consequences. A 35-year follow-up of over 500 individuals with AD yielded a mortality estimate of 4.4 percent (Millar et al., 2005). Although the majority of deaths from AD occur in young adults, a Norwegian study of AD–related deaths found that 43 percent of the deaths occurred in women age 65 and older (Reas et al., 2005). Women with AD die not only from the complications of their disorder, but from suicide. The highest rates of suicide attempts (25 percent) occur in women who have comorbid depression and the binging/purging form of the disorder (Forcano et al., 2011).
People who have AD experience a core disturbance in their body image. They are dissatisfied with their bodies and believe that their bodies are larger than they really are. In one fMRI study, women with anorexia nervosa showed distinct arousal patterns in areas of the brain involved in processing emotion (Mohr et al., 2010). Women with AD also seem to engage in social comparison processes when they view other women’s bodies. An fMRI study compared women’s limbic system activation with AD when seeing their own and other women’s bodies. Their amgydala showed greater activation at viewing other women’s bodies (Vocks et al., 2010). Women with the restrictive form of AD appear not to value thinness so much as they are repelled by the idea of being overweight (Cserjési et al., 2010).
The lifetime prevalence of AD is 0.9 percent for women and 0.3 percent for men. In addition, people with anorexia nervosa have higher rates of mood, anxiety, impulsecontrol, and substance use disorders. The majority of individuals who develop anorexia nervosa between their early teenage years and their early 20s have the disorder for 1.7 years. Men have 25 percent lower lifetime prevalence than women (Hudson, Hiripi, Pope, & Kessler, 2007).