Article

Increased Dopamine D2/D3 Receptor Binding After Recovery from Anorexia Nervosa Measured by Positron Emission Tomography and [11C]Raclopride

Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
Biological Psychiatry (Impact Factor: 10.26). 01/2006; 58(11):908-12. DOI: 10.1016/j.biopsych.2005.05.003
Source: PubMed

ABSTRACT

Several lines of evidence support the possibility that disturbances of dopamine (DA) function could contribute to alterations of weight, feeding, motor activity, and reward in anorexia nervosa (AN).
To assess possibly trait-related disturbances but avoid confounding effects of malnutrition, 10 women who were recovered from AN (REC AN) were compared with 12 healthy control women (CW). Positron emission tomography with [(11)C]raclopride was used to assess DA D2/D3 receptor binding.
The women who were recovered from AN had significantly higher [(11)C]raclopride binding potential in the antero-ventral striatum than CW. For REC AN, [(11)C]raclopride binding potential was positively related to harm avoidance in the dorsal caudate and dorsal putamen.
These data lend support for the possibility that decreased intrasynaptic DA concentration or increased D2/D3 receptor density or affinity is associated with AN and might contribute to the characteristic harm avoidance or increased physical activity found in AN. Most intriguing is the possibility that individuals with AN might have a DA related disturbance of reward mechanisms contributing to altered hedonics of feeding behavior and their ascetic, anhedonic temperament.

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    • "These studies revealed a predominant imbalance between the reward and inhibition systems of the brain, which are hallmark characteristics of the disorder. Recovered AN patients show increased dopamine receptor availability ( Frank et al., 2005 ) and also functional magnetic resonance imaging (fMRI) studies point to dopamine dysfunction by discovering hypoactivity of striatal regions in response to pleasurable stimuli ( Kaye et al., 2009 ). This resulted in the notion that AN patients suffer from general anhedonia unable to experience pleasure. "
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    • "Clinically, pure restrictor-type AN individuals are often over-controlled, over-concerned about consequences, and perfectionistic [9]–[12]. They also tend to be anhedonic and ascetic, able to sustain self-denial of food as well as most comforts and pleasures in life [13]. Although the understanding of the pathophysiology of AN and other eating disorders has lagged behind other major psychiatric disorders, a growing body of evidence suggests that AN is a neurobiologically based disorder characterized by alterations in neurocircuitry supporting inhibition and cognitive control [9], [14]–[21]. "
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    • "ol participants , recov - ered AN adults showed excessive activation of the caudate , regardless of trial type , and abnormal activation of the ventral striatum during negative feedback on a guessing game . Together with PET evidence indicating increased D2 / D3 receptor bind - ing in the ventral striatum in both ill and recovered adults with AN ( Frank et al . , 2005 ) , these findings suggest that impaired reward processing within the ventral striatum may contribute to the diminished motivation to eat , as food may not be as rewarding to these individuals as it is to others . Although inter - esting , these data do not inform us about habit learning capabilities within the dorsolateral striatum in "
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