The Paradox of Anorexia Nervosa without Drive for Thinness

About 50% of people with eating disorders have “atypical” or partial-syndrome disorders. Some patients have only some of the criteria for a DSM-IV diagnosis, while others have all the criteria but do not show the core psychological features of AN. Drive for thinness, or a morbid fear of fat and of gaining weight is one of the main components of AN.

Giovanni Abbate-Daga, MD and colleagues at the University of Turin, Italy, recently studied a group of 151 women with AN (Psychiatry Res. 2007; 149:215), to compare differences between women with typical and atypical AN (atypical AN was defined as patients without an explicit or obvious drive for thinness). The women were assessed for nutritional state and eating disorder and body mass index (BMI), and took the Eating Disorders Inventory-2, the Beck Depression Inventory, the State-Trait Anger Expression Inventory (STAXI), and the Temperament and Character Inventory (TCI), among others. The Drive for Thinness (DT) subscale of the EDI-2 measures preoccupation with body weight, excessive concern with dieting, and a morbid fear of becoming fat. The scale runs from 0 to 21.

Three subgroups studied

The patients were divided into three subgroups on the basis of BMI and DT score: AN-I, a BMI <15 (AN-I) and a DT score <7; AN-II, a BMI> 15 and DT < 7 (AN-II), and ANIII, a BMI <17.5 and DT >7. In this study, patients had DT scores ranging from a low of 1.45 to a high of 14.6. Those in the last group had more severe illness and psychopathology, based on their scores. There was no association between personality disorders and any single subgroup.

Less severe disease was reported in the atypical group

This study featured a higher-than-normal percentage of patients with atypical anorexia (n= 58, or 38% of the total group). The authors reached three conclusions. First, some patients (about 38%) denied having DT, and provided negative answers on the questionnaires. Second, patients without DT (even when malnourished) seemed to show less severe psychopathology and personality traits. Third, patients with DT answered questions honestly but had developed a character structure that enabled them to feel negative and ego-dystonic emotions about their condition.

The study results also supported the psychopathologic differences between “typical” anorectics with high DT scores and atypical anorectics without DT. Typical anorectics seemed more severely ill than did the atypical patients. The severity of eating attitudes and of anger expression was greater in typical anorectics than in the atypical ones, those with a BMI >15 (AN-II) and those with a BMI <15 (AN-I).

The results on the TCI only complicated the attempt to explain the paradox of AN without DT. The authors hypothesize that severely emaciated patients with a low DT do not consciously lie when answering self-report questions, but instead have personalities that don’t allow them to feel negative emotions about their physical condition and life.