Objective
Using single photon emission computed tomography (SPECT), we sought brain perfusion correlates of eating disorder symptoms in anorexia and bulimia nervosa patients.
Method
We investigated 67 female eating disordered (ED) patients. Eating disorder symptoms were measured by the Eating Disorders Inventory (EDI). Determination of brain areas in which regional perfusion co-varied with drive for thinness, bulimia, body dissatisfaction, ineffectiveness, perfectionism, interpersonal distrust, interoceptive awareness and maturity fears was done by open explorative correlation analysis using Statistical Parametrical Mapping (SPM).
Results
A significant positive correlation between scores on body dissatisfaction and ineffectiveness, and brain perfusion in the prefrontal and parietal cortex was demonstrated. There were no correlations between other eating disorder symptoms and brain perfusion.
Conclusion
Based on the finding of an association between regional brain flow and body dissatisfaction and ineffectiveness, we argue that neurobiological findings in ED patients may not only reflect emotional and behavioural factors but cognitive–evaluative features as well.
Eating disorder (ED) research is increasingly focusing on the precipitating factors for disordered eating behaviour. Such factors range from cultural over social and familial interactions to narrowly biological factors. Also, psychological features such as cognition and affective states may be involved. Moreover, the relationship between these antecedents and (disordered) eating behaviour seems complex (Polivy and Herman, 2002).
Recent research has shown that body dissatisfaction (BD) is a prominent risk factor (Stice and Shaw, 2002), and most conceptualisations of EDs, including DSM, make reference to it. BD refers to negative evaluations of one’s body, such as shape, size and weight. This dissatisfaction is primarily a function of the obsession with thinness and/or fear of weight gain (Harvey et al., 2002 and Williamson et al., 2002). Importantly, a central feature in both anorexia (AN) and bulimia nervosa (BN) is the use of one’s body weight and shape as the basis for self-evaluation (McFarlane et al., 2001 and McFarlane et al., 1998). Thus, negative feelings about the self are associated with negative feelings about the body, although the direction of the association is not clear.
EDs also feature several cognitive dysfunctions, including obsessive thoughts (Halmi et al., 2003), and attentional and memory bias, especially for material related to food, body weight and shape (Lee and Shafran, 2004). Usually, attention is measured by the performance on experimental strategies. However, performance can be either facilitated or impaired due to the selective processing of information related to the person’s concerns. For example, in the Stroop Colour Word test, colour naming is significantly slowed if the ink colour and meaning of the colour word differ (MacLeod, 1991). Similarly, in the emotional version of the Stroop test, performance is impaired if the presented words are personally and emotionally salient in comparison with words that are emotionally neutral (Taghavi et al., 2003). With EDs, this means that performance is disturbed when the words to be colour named are related to food and body size and shape (Dobson and Dozois, 2004). Further, ED patients tend to spend a great amount of time obsessing about food, eating, and related matters (Sunday et al., 1995), inasmuch that an obsession with becoming thin may be seen as the driving force of both AN and BN. Another putative causal obsession-related factor is the strive to be perfect (Shafran et al., 2002). Perfectionism is readily applied to eating, weight and shape, and ED patients desperately become invested in achieving a perfect body.
In this study, we investigated a group of female AN and BN patients with brain perfusion SPECT and sought regional perfusion correlates of ED symptoms measured with the Eating Disorders Inventory (EDI) (Garner et al., 1983). Because BD is presumed to be primarily a function of body image disturbances (Gupta and Johnson, 2000), including both perceptual body size distortion and cognitive–evaluative disturbances (Fassino et al., 2002 and Skrzypek et al., 2001), we hypothesized that particularly BD would be associated with regional cerebral blood flow (rCBF) in brain regions that are assumed to mediate the foregoing functions, i.e. in a network of frontal and parietal cortical areas. The study was carried out in accordance with the latest version of the Declaration of Helsinki and approved by the local ethics committee. Written informed consent was obtained from each subject after the procedure had been fully explained.
