Role of the ventral striatum in developing anorexia nervosa

Abstract

Functional imaging data in adult patients with anorexia nervosa (AN) support a dysfunctional signal in the ventral striatum as neural signature of AN. In the present study, development of this signal was investigated with the prediction that a characteristic pattern of ventral–striatal signalling will be shown in response to cues associated with food restriction that reflects the evolvement of starvation dependence over time. The signal was assessed in adolescent patients with AN, whose duration of illness was about five times shorter relative to the adult sample. During functional magnetic resonance imaging subjects were required to estimate weights of body images (underweight, normal weight, overweight) and to process each stimulus in a self-referring way. Relative to age-matched, young healthy controls, underweight stimuli were already associated with greater activity of the ventral striatum, and processing of normal-weight stimuli elicited already reduced signalling. Subjective preferences showed exactly the same pattern of results. Relative to adult AN, the present data reveal a developing dysfunctional signal that, if untreated, will essentially contribute to the maintenance of AN. We discuss putative mechanisms that may play a crucial role in the development of AN, and also deduce new hypotheses about the involvement of the midbrain dopamine system, of which illness-related alterations may contribute to the development of AN.

An investigation of habit learning in Anorexia Nervosa

“…However, whilst these studies suggest that AN may not involve a generalised vulnerability to forming habits, disorder-specific habits in AN warrant further investigation. Individuals with AN experience intense reward from the pursuit of thinness (Park et al, 2014), reflected by increased salience and neural response to disorder-related stimuli in reward and habit-related regions in AN (Cowdrey et al, 2011; Fladung et al, 2010; Fladung et al, 2013; Foerde et al, 2015; Giel et al, 2013). Food restriction is linked to an upregulation of reward (Fulton et al, 2004), and as such this may further increase the rewarding value of weight-loss behaviour in individuals with AN.…”

A novel measure of compulsive food restriction in anorexia nervosa: Validation of the Self-Starvation Scale (SS)

“…A longitudinal research design would allow further investigation of the role of compulsive weight loss behaviour in the development and maintenance of AN. Finally, the AN sample was relatively small and future studies will benefit from extension to larger samples, allowing differentiation by subtype, and at different ages and stages of AN, especially given neuroscientific evidence that reward deficits in AN may vary with AN subtype (Kaye et al, 2013) and accrue with length of illness (Fladung, Schulze, Schöll, Bauer, & Grön, 2013;Park et al, 2014).…”

Compulsivity in anorexia nervosa: a transdiagnostic concept

“…(2) Weight loss is experienced as rewarding, which may be positively reinforced by an increase of DA in the VS. (3) The pursuit of the rewarding aspects of weight loss leads to a repetition of weight loss behaviors: (a) disorder related cues may gain incentive salience through conditioned reinforcement, and may themselves trigger weight loss behavior (Walsh, 2013). (4) Repetition of rewarding weight loss behavior may result in synaptic changes in DA pathways (Fladung et al, 2013) and result in DA hypofunctioning in a similar way to substance dependence (Everitt and Robbins, 2005). (5) The avoidance of negative states and the anxiety associated with food may become more important in reinforcing weight loss behaviors in the later stages of AN (Selby et al, 2014).…”