Altered 5-HT2A Receptor Binding after Recovery from Bulimia-Type Anorexia Nervosa: Relationships to Harm Avoidance and Drive for Thinness

Abstract

Several lines of evidence suggest that a disturbance of serotonin neuronal pathways may contribute to the pathogenesis of anorexia nervosa (AN) and bulimia nervosa (BN). This study applied positron emission tomography (PET) to investigate the brain serotonin 2A (5-HT 2A ) receptor, which could contribute to disturbances of appetite and behavior in AN and BN. To avoid the confounding effects of malnutrition, we studied 10 women recovered from bulimia-type AN (REC AN-BN, 41 year normal weight, regular menstrual cycles, no binging, or purging) compared with 16 healthy control women (CW) using PET imaging and a specific 5-HT 2A 18 F]altanserin binding potential and drive for thinness in several cortical regions. In conclusion, this study extends research suggesting that altered 5-HT neuronal system activity persists after recovery from bulimia-type AN, particularly in subgenual cingulate regions. Altered 5-HT neurotransmission after recovery also supports the possibility that this may be a trait-related disturbance that contributes to the pathophysiology of eating disorders. It is possible that subgenual cingulate findings are not specific for AN-BN, but may be related to the high incidence of lifetime major depressive disorder diagnosis in these subjects.

Neurobiology of anorexia and bulimia nervosa

“…The well-known distortion of body image in individuals with AN may suggest abnormalities of circuits through the postulated 'self' networks. In line with this, left parietal cortical activation has previously been linked to AN womens' evaluation of body image (115,116).…”

“…These studies reported a hyper-responsiveness in brain areas belonging to the frontal visual system and the attention network (BA 9) as well as inferior parietal lobule (BA 40), including the anterior part of the intraparietal (IPL) sulcus. Bailer (116) reported negative relationships between 5-HT 2A receptor activity and the Eating Disorder Inventory Drive for Thinness scale in the left parietal cortex and other regions. It is intriguing to raise the possibility that left hemisphere disturbances of this pathway may contribute to body image distortion.…”

Altered brain activity in women recovered from bulimic-type eating disorders after a glucose challenge: A pilot study

“…Other imaging studies have found altered serotonergic activity in similar cingulate regions in BN subjects. 11,20 Moreover, Uher et al 21 reported that pictures of food increased activity in the ACC and other regions in BN subjects compared with CW.…”

Genetic epidemiology, endophenotypes, and eating disorder classification

“…86 In women recovered from bulimia-type AN, [ 18 F]altanserin binding potential and drive for thinness were negatively correlated in several cortical regions, suggesting that altered 5-HT neuronal system activity persisted. 87 Given that different measures have been used to capture these cognitive features, further work is required to increase the reliability and validity of these measures before conclusions can be drawn about their potential status as an eating disorder endophenotype, including the degree to which they are influenced by genetic factors.…”