People routinely make poor choices, despite knowledge of negative consequences. The authors found that individuals with anorexia nervosa, who make maladaptive food choices to the point of starvation, ...engaged the dorsal striatum more than healthy controls when making choices about what to eat, and that activity in fronto-striatal circuits was correlated with their actual food consumption in a meal the next day.
Abstract Background Individuals with anorexia nervosa (AN) override the drive to eat, forgoing immediate rewards in favor of longer-term goals. We examined delay discounting and its neural correlates ...in AN before and after treatment to test a potential mechanism of illness persistence. Methods Inpatients with AN ( n = 59) and healthy control subjects (HC, n = 39) performed a delay discounting task at two time points. A subset ( n = 30 AN, n = 22 HC) participated in functional magnetic resonance imaging scanning during the task. The task consisted of a range of monetary choices with variable delay times, yielding individual discount rates—the rate by which money loses value over time. Results Before treatment, the AN group showed a preference for delayed over earlier rewards (i.e., less steep discount rates) compared with HC; after weight restoration, AN did not differ from HC. Underweight AN showed slower response times for earlier versus delayed choices; this reversed with treatment. Underweight AN showed abnormal neural activity in striatum and dorsal anterior cingulate; normalization of behavior was associated with increased activation in reward regions (striatum and dorsal anterior cingulate) and decision-making regions (dorsolateral prefrontal cortex and parietal cortex). Conclusions The undernourished state of AN may amplify the tendency to forgo immediate rewards in favor of longer-term goals. The results suggest that behavior that looks phenotypically like excessive self-control does not correspond with enhanced prefrontal recruitment. Rather, the results point to alterations in cingulostriatal circuitry that offer new insights on the potential role of abnormalities in decision-making neural systems in the perpetuation of AN.
The National Institute of Mental Health launched the Research Domain Criteria (RDoC) initiative to better understand dimensions of behavior and identify targets for treatment. Examining dimensions ...across psychiatric illnesses has proven challenging, as reliable behavioral paradigms that are known to engage specific neural circuits and translate across diagnostic populations are scarce. Delay discounting paradigms seem to be an exception: they are useful for understanding links between neural systems and behavior in healthy individuals, with potential for assessing how these mechanisms go awry in psychiatric illnesses. This article reviews relevant literature on delay discounting (or the rate at which the value of a reward decreases as the delay to receipt increases) in humans, including methods for examining it, its putative neural mechanisms, and its application in psychiatric research. There exist rigorous and reproducible paradigms to evaluate delay discounting, standard methods for calculating discount rate, and known neural systems probed by these paradigms. Abnormalities in discounting have been associated with psychopathology ranging from addiction (with steep discount rates indicating relative preference for immediate rewards) to anorexia nervosa (with shallow discount rates indicating preference for future rewards). The latest research suggests that delay discounting can be manipulated in the laboratory. Extensively studied in cognitive neuroscience, delay discounting assesses a dimension of behavior that is important for decision-making and is linked to neural substrates and to psychopathology. The question now is whether manipulating delay discounting can yield clinically significant changes in behavior that promote health. If so, then delay discounting could deliver on the RDoC promise.
Objective
Anorexia Nervosa (AN) is a serious disorder, with a mortality rate the highest of any psychiatric illness. It is notoriously challenging to treat and mechanisms of illness are not well ...understood. Reward system abnormalities have been proposed across theoretical models of the persistence of AN. Feedback learning is an important component of how reward systems shape behavior and we hypothesized that individuals with AN would show poorer learning from feedback.
Methods
We administered the acquired equivalence task to measure both learning from incremental feedback and generalization of that learning to novel stimuli. Participants were individuals with AN (n = 36) before and after intensive weight restoration treatment and healthy comparison participants (HC, n = 26) tested twice. Performance was assessed as accuracy during the Learning and Test phases, for both trained and novel stimuli. The relationship between task performance and eating disorder severity at baseline was also assessed.
Results
Both before and after treatment, individuals with AN showed reduced learning from feedback in the Learning phase (F3,180 = 2.75, p = .048) and lower accuracy during the Test phase (F1,60 = 4.29, p = .043), as compared with HC. Individuals with AN did not differ from HC in accuracy for novel stimuli (F1,60 = 1.04, p = .312), indicating no deficit in generalization. Decreased acquisition of feedback learning was associated with longer illness duration and with greater eating disorder symptom severity at baseline.
Conclusions
Individuals with AN show reduced learning from feedback or reinforcement, which may contribute to difficulties in changing maladaptive behaviors.
Eating behavior in atypical anorexia nervosa Jablonski, Monica; Schebendach, Janet; Walsh, B. Timothy ...
The International journal of eating disorders,
April 2024, 2024-Apr, 2024-04-00, 20240401, Letnik:
57, Številka:
4
Journal Article
Recenzirano
Objective
Atypical anorexia nervosa (AN) has been increasingly identified in the community and in clinical settings. Initial studies indicate that psychological symptoms are similar or more severe ...among patients with atypical AN, as compared with AN. This study examined whether eating behavior differed among patients with AN (n = 98), patients with atypical AN (n = 18), and healthy controls (HC, n = 75).
Method
Adults and adolescents chose what to eat from a standardized, laboratory‐based multi‐item meal. Total intake, macronutrient composition, diet variety, and energy density were compared between groups.
Results
Both AN and atypical AN severely restricted caloric intake as compared with HC (431 ± 396 kcal and 340 ± 338 kcal vs. 879 ± 350 kcal, F2,188 = 35.4, p < .001). Individuals with AN and atypical AN did not differ in the mean intake of total calories or percentage of calories from fat (15.2 ± 25.2% vs. 11.5 ± 16.9%).
Discussion
This study demonstrates that individuals with atypical AN are at least as restrictive in their food intake as individuals with AN, and the restriction of dietary fat is particularly notable. Examination of eating behavior in a larger sample would be useful to replicate these findings. The current study highlights the need to understand maladaptive eating behavior in atypical AN in order to develop appropriate treatment recommendations.
Public Significance
Atypical anorexia nervosa is emerging as a prevalent eating disorder in community and clinical populations. The findings that patients with atypical anorexia nervosa limit calorie and fat intake in a pattern similar to that of patients with anorexia nervosa highlights the need for research to identify appropriate treatment strategies for normalization of eating patterns.
Increased capacity to delay reward in anorexia nervosa Steinglass, Joanna E; Figner, Bernd; Berkowitz, Staci ...
Journal of the International Neuropsychological Society,
07/2012, Letnik:
18, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Individuals with anorexia nervosa (AN) are often characterized as possessing excessive self-control and are unusual in their ability to reduce or avoid the consumption of palatable foods. This ...behavior promotes potentially life-threatening weight loss and suggests disturbances in reward processing. We studied whether individuals with AN showed evidence of increased self-control by examining the tendency to delay receipt of a monetary, non-food related, reward. Underweight AN (n = 36) and healthy controls (HC, n = 28) completed a monetary intertemporal choice task measuring delay discounting factor. Individuals with AN reduced the value of a monetary reward over time significantly less than HC (F1,61 = 5.03; p = 0.029). Secondary analyses indicated that the restricting subtype of AN, in particular, showed significantly less discounting than HC (F1,46 = 8.3; p = 0.006). These findings indicate that some individuals with AN show less temporal discounting than HC, suggestive of enhanced self-control that is not limited to food consumption. This is in contrast to other psychiatric disorders, for example, substance abuse, which are characterized by greater discounting. Though preliminary, these findings suggest that excessive self-control may contribute to pathological processes and individuals with AN may have neuropsychological characteristics that enhance their ability to delay reward and thereby may help to maintain persistent food restriction.
Cognitive Neuroscience of Eating Disorders Steinglass, Joanna E; Berner, Laura A; Attia, Evelyn
The Psychiatric clinics of North America,
03/2019, Letnik:
42, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Anorexia nervosa and bulimia nervosa are characterized by severely restricted intake, binge eating, and compensatory behaviors like self-induced vomiting. The neurobiological underpinnings of these ...maladaptive behaviors are poorly understood, but the application of cognitive neuroscience and neuroimaging to eating disorders has begun to elucidate their pathophysiology. Specifically, this review focuses on 3 areas that suggest paths forward: reward, cognitive and behavioral control, and decision making. Understanding the brain-based mechanisms that promote and maintain these often chronic symptoms could guide the development of new and more effective treatments.
Objective
Psychiatric illnesses, like medical illnesses, can sometimes be considered as progressing through stages. Understanding these stages can lead to a better understanding of pathophysiology, ...and clarification of prognosis and treatment needs. Opinions from experts in the field of anorexia nervosa (AN) were sought to create a model of stages of illness.
Method
The Delphi approach was used to achieve consensus from a panel of 31 individuals from a range of disciplines with expertise in AN. Over three iterative rounds, participants rated agreement with statements about an overall staging framework and definitions of specific stages.
Results
Agreement was reached about a longitudinal progression including Subsyndromal, Full Syndrome, Persistent Illness, and Partial and Full Remission. The panel achieved consensus in defining Subsyndromal AN as characterized by body image disturbance and mild to moderate restrictive eating. Overall, there was consensus that restrictive eating is central to the behavioral features of all stages of AN, and agreement that its absence is essential to any stage of health. There was little consensus about biological markers, other than body mass index, and no consensus about quality of life indices associated with different stages.
Discussion
This panel discussion yielded an expert‐informed staging model for AN. This model now needs to be tested for its validity. The lack of consensus in several areas highlighted other research questions to address in order to develop an empirically valid and scientifically useful model of the progression of AN.
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