Neural activations are related to body-shape, anxiety, and outcomes in adolescent anorexia nervosa

Abstract

Anorexia nervosa (AN) is an illness that frequently begins during adolescence and involves weight loss. Two groups of adolescent girls (AN-A, weight-recovered following AN) and (HC-A, healthy comparison) completed a functional magnetic resonance imaging task involving social evaluations, allowing comparison of neural activations during self-evaluations, friend-evaluations, and perspective-taking self-evaluations. Although the two groups were not different in their whole-brain activations, anxiety and body shape concerns were correlated with neural activity in a priori regions of interest. A cluster in medial prefrontal cortex and the dorsal anterior cingulate correlated with the body shape questionnaire; subjects with more body shape concerns used this area less during self than friend evaluations. A cluster in medial prefrontal cortex and the cingulate also correlated with anxiety such that more anxiety was associated with engagement when disagreeing rather than agreeing with social terms during self-evaluations. This data suggests that differences in the utilization of frontal brain regions during social evaluations may contribute to both anxiety and body shape concerns in adolescents with AN. Clinical follow-up was obtained, allowing exploration of whether brain function early in course of disease relates to illness trajectory. The adolescents successful in recovery used the posterior cingulate and precuneus more for friend than self evaluations than the adolescents that remained ill, suggesting that neural differences related to social evaluations may provide clinical predictive value. Utilization of both MPFC and the precuneus during social and self evaluations may be a key biological component for achieving sustained weight-recovery in adolescents with AN.

Strengthened Default Mode Network Activation During Delay Discounting in Adolescents with Anorexia Nervosa After Partial Weight Restoration: A Longitudinal fMRI Study

“…First, they deliver evidence suggestive of a partial normalization of neural processes subserving DD, after short-term weight restoration. The longitudinal changes in DMN activation observed here during performance of a DD task dovetail with previous findings of alterations in these regions in individuals with AN, both at rest [66,67] and during other self-relevant decision-making tasks [69][70][71][72]. Although supplementary analyses of functional connectivity between the identified DMN regions and task-positive FPN regions did not detect significant longitudinal differences, future-focused analysis of antagonism between task-positive and task-negative networks [83] might provide a unique window on brain function and dysfunction in AN [84][85][86].…”

“…However, suggesting that normalization was only partial and regionally specific, dACC activation generally increased in acAN-TP2, but still did not exhibit a normal response on difficult vs. easy trials [59], as observed previously in both HC and recAN [20,40]. Second, while aberrant DMN function has been repeatedly described in AN, both at rest [66,67] and during disorder-relevant stimulation [68][69][70][71][72], the apparent longitudinal improvement observed here in a task that recruited the FPN, suggests that the abnormalities might be primarily associated with the underweight state and might not constitute a trait variable of the disorder. Based on our previous findings of consistently faster decision-making and altered neural efficiency in the FPN during DD in acAN compared to HC [40], we speculate that the relative attenuation of DMN deactivation in acAN-T2 might reflect a relaxation of excessive self-control over the course of treatment or a shift from more habitual to intentional execution of self-control.…”

“…Given the self-relevant nature of intertemporal choices [32,73], the involvement of DMN in self-referential processing [74,75] and the notion that AN is characterized by fundamental disturbances in self-identity [28][29][30], another interpretation of increased DMN activation after weight restoration is that it might reflect improved self-regulation and the ability to integrate self-relevant signals in decision-making. The likelihood of this alternative account is supported by findings of differences in DMN activation in AN samples in various tasks involving self-perception and evaluation [69][70][71][72]. Last but not the least, regardless of which interpretation best fits the data, the observed longitudinal activation changes in a task with good group-level test-retest reliability [50] underlines the notion that DD might not be a static trait, as is often thought [76,77], but is rather a highly malleable and task-dependent process [78].…”

The Neurobiology of Eating Disorders

“…During a self-and-other social evaluation task, anxiety and body shape concerns correlated inversely in participants with AN compared with controls, with prefrontal and cingulate brain response, implicating those regions. 90 Gentle touch or intimate visual stimuli were rated less pleasant in participants with AN compared with controls, and were associated with lower caudate or parietal activity, suggesting reduced reward experience. 91,92…”

Intimate stimuli result in fronto-parietal activation changes in anorexia nervosa

“…Additionally, this region shows significant grey matter loss in AN, and it might particularly also be susceptible to the effects of AN in the long run [53,61,62]. Xu et al [63] recently pointed to the importance of the precuneus and the medial prefrontal cortex during social evaluations in AN, including a possible predictive value.…”