Reduced dorsal fronto-striatal connectivity at rest in anorexia nervosa.

BACKGROUND: Anorexia nervosa (AN) is a serious psychiatric illness that remains difficult to treat. Elucidating the neural mechanisms of AN is necessary to identify novel treatment targets and improve outcomes. A growing body of literature points to a role for dorsal fronto-striatal circuitry in the pathophysiology of AN, with increasing evidence of abnormal task-based fMRI activation within this network among patients with AN. Whether these abnormalities are present at rest and reflect fundamental differences in brain organization is unclear. METHODS: The current study combined resting-state fMRI data from patients with AN (n = 89) and healthy controls (HC; n = 92) across four studies, removing site effects using ComBat harmonization. First, the a priori hypothesis that dorsal fronto-striatal connectivity strength - specifically between the anterior caudate and dlPFC - differed between patients and HC was tested using seed-based functional connectivity analysis with small-volume correction. To assess specificity of effects, exploratory analyses examined anterior caudate whole-brain connectivity, amplitude of low-frequency fluctuations (ALFF), and node centrality. RESULTS: Compared to HC, patients showed significantly reduced right, but not left, anterior caudate-dlPFC connectivity (p = 0.002) in small-volume corrected analyses. Whole-brain analyses also identified reduced connectivity between the right anterior caudate and left superior frontal and middle frontal gyri (p = 0.028) and increased connectivity between the right anterior caudate and right occipital cortex (p = 0.038). No group differences were found in analyses of anterior caudate ALFF and node centrality. CONCLUSIONS: Decreased coupling of dorsal fronto-striatal regions indicates that circuit-based abnormalities persist at rest and suggests this network may be a potential treatment target.

Eating Disorders.

Eating disorders are common behavioral disorders associated with substantial psychological and physical morbidity and mortality. Persons with eating disorders frequently present to primary care providers, who may also be responsible for their general medical management. This article reviews the diagnosis, medical assessment, and treatment of the most common eating disorders.

Predictors of eating-related psychopathology in transgender and gender nonbinary individuals.

OBJECTIVE: Research examining the prevalence and severity of eating-related psychopathology in transgender and gender nonbinary individuals is limited. This study examined how identity development and minority stress relate to the presence of disordered eating behaviors and cognitions in transgender and gender nonbinary individuals, and improvement at one-year follow-up. METHODS: Data come from a multi-site, longitudinal study of transgender and gender nonbinary individuals (n = 287) and includes assessment of transgender congruence, receipt of gender-affirming care, minority stress, and disordered eating symptoms. Hierarchical multivariable logistic regression was used to test for associations between identity development, minority stress, and eating-related psychopathology. RESULTS: Eighty-three participants (28.9%) met criteria for current eating-related psychopathology. Loss of control eating was the most commonly endorsed behavior, followed by laxative, diuretic, or other medication use, and compulsive exercise. Higher transgender congruence was associated with lower odds of disordered eating symptoms (OR = 0.72, 95% CI 0.55-0.94), whereas increased internalized transphobia was associated with greater odds of disordered eating symptoms (OR = 1.41, 95% CI = 1.04-1.91). Participants with eating-related psychopathology had greater odds of having received gender-affirming psychotherapy in the year prior to assessment (OR = 2.33, 95% CI = 1.32-4.14). CONCLUSIONS: Results suggest that gender identity development and internalized transphobia are associated with eating-related psychopathology in transgender and gender nonbinary individuals. Mental health providers should consider assessing all transgender and gender nonbinary individuals for eating-related psychopathology and unique risk factors associated with disordered eating, including low transgender congruence and internalized transphobia.

A comparison of food-based decision-making between restricting and binge-eating/purging subtypes of anorexia nervosa.

OBJECTIVE: By definition, restricting (ANR) and binge-eating/purging (ANBP) subtypes of anorexia nervosa (AN) differ in some manifestations of maladaptive eating behavior. This study aimed to determine whether the groups differ in the choices they make about what to eat, and whether there are differences in valuation related to food choice, using an experimental paradigm. METHOD: Inpatients with ANR (n = 40) and ANBP (n = 46) participated in a Food Choice Task. During the task, participants rated 76 food images for healthiness and tastiness, and choice preferences. Groups were compared in percent selection of high-fat and low-fat foods, value ratings of foods, and engagement of self-control in food choice. RESULTS: There were no differences between AN subtypes in healthiness or tastiness ratings, or in tendency to limit choice of high-fat foods. There was no difference between the groups in measures of self-control in food choice. DISCUSSION: Individuals with ANR and ANBP similarly manifest reduced choices of high-fat foods, with similar tendencies to undervalue the tastiness of high-fat foods. These results suggest that while individuals with ANR and ANBP differ across a range of clinical characteristics, the decision-making process associated with the maladaptive restriction of high-fat foods characteristic of AN is shared by both subtypes.

Weight suppression and weight maintenance following treatment of anorexia nervosa.

OBJECTIVE: The value of weight suppression (WS) in predicting the course of anorexia nervosa (AN) is uncertain. The objective of this study was to determine, using data from a previously published study, whether patients who remain weight suppressed following restoration to a minimally normal weight are at greater risk for relapse. METHOD: Following weight restoration, 93 women with AN were randomly assigned to receive fluoxetine or placebo along with cognitive behavioral therapy for 1 year. WS (highest adult weight minus current weight), body mass index (BMI), and their interaction were assessed as predictors of change in weight over the first 28 days, of successful weight maintenance at 6 and 12 months, and of time to relapse. RESULTS: Neither WS nor its interaction with BMI predicted successful weight maintenance at 6 and 12 months, time to relapse, or weight change over the first 28 days following discharge. DISCUSSION: This study found that WS does not substantially impact the likelihood of successful weight maintenance or time to relapse following restoration to a minimally normal weight in AN.

Fat preference and fat intake in individuals with and without anorexia nervosa.

Fat restriction is a characteristic eating behavior among individuals with anorexia nervosa (AN), and laboratory meal studies demonstrate restricted fat intake among low-weight patients. The Geiselman Food Preference Questionnaire-I© (FPQ) is a validated self-report measure that yields a fat preference score (FPS). Prior research reported that patients with AN had a significantly lower FPS than did healthy control (HC) participants. The goal of the current study was to compare self-reported fat preference (FPS) to fat intake (multi-item meal (MIM) study) in low-weight ANs and HCs. Specific aims were 1) to determine if the FPS differed between ANs and HCs; 2) to determine if fat and energy intakes differed between ANs and HCs; and 3) to determine if the FPS was associated with fat and energy intakes in ANs and HCs. Forty-four female AN inpatients and 48 female HCs completed the FPQ and participated in a MIM study. Compared to HCs, ANs consumed less energy (469.1 ±â€¯397.7 vs. 856.4 ±â€¯346.8 kcal, p < 0.001), less fat (16.4 ±â€¯20.4 vs. 36.7 ±â€¯18.9 g, p < 0.001), and a smaller percentage of calories from fat (22.9 ±â€¯13.8 vs. 36.6 ±â€¯8.0%, p < 0.001) at the MIM. Compared to HCs, ANs also had a lower FPS (79.7 ±â€¯27.4 vs. 102.3 ±â€¯18.9, p < 0.001). The FPS was significantly and positively correlated with caloric intake (r = 0.481, p < 0.01), total fat (r = 0.453, p < 0.01), and the percentage of calories from fat (r = 0.37, p < 0.05) in ANs as well as in HCs (kcal: r = 0.583, p < 0.001; fat: r = 0.621, p < 0.001; % fat kcal: r = 0.601, p < 0.001). The FPS is related to objective measures of energy and fat intake in patients with AN as well as in healthy individuals.

Resting-state connectivity within and across neural circuits in anorexia nervosa.

INTRODUCTION: Obsessional thoughts and ritualized eating behaviors are characteristic of Anorexia Nervosa (AN), leading to the common suggestion that the illness shares neurobiology with obsessive-compulsive disorder (OCD). Resting-state functional connectivity MRI (rs-fcMRI) is a measure of functional neural architecture. This longitudinal study examined functional connectivity in AN within the limbic cortico-striato-thalamo-cortical (CSTC) loop, as well as in the salience network, the default mode network, and the executive control network (components of the triple network model of psychopathology). METHODS: Resting-state functional connectivity MRI scans were collected in unmedicated female inpatients with AN (n = 25) and healthy controls (HC; n = 24). Individuals with AN were scanned before and after weight restoration and followed for one month after hospital discharge. HC were scanned twice over the same timeframe. RESULTS: Using a seed-based correlation approach, individuals with AN had increased connectivity within the limbic CSTC loop when underweight, only. There was no significant association between limbic CSTC connectivity and obsessive-compulsive symptoms or prognosis. Exploratory analyses of functional network connectivity within the triple network model showed reduced connectivity between the salience network and left executive control network among AN relative to HC. These abnormalities persisted following weight restoration. CONCLUSIONS: The CSTC findings suggest that the neural underpinnings of obsessive-compulsive symptoms may differ from those of OCD. The inter-network abnormalities warrant examination in relation to illness-specific behaviors, namely abnormal eating behavior. This longitudinal study highlights the complexity of the neural underpinnings of AN.

The Role of Habits in Anorexia Nervosa: Where We Are and Where to Go From Here?

PURPOSE OF REVIEW: The persistent maladaptive eating behavior characteristic of anorexia nervosa (AN) can be understood as a learned habit. This review describes the cognitive neuroscience background and the existing data from research in AN. RECENT FINDINGS: Behavior is habitual after it is frequently repeated and becomes nearly automatic, relatively insensitive to outcome, and mediated by dorsal frontostriatal neural systems. There is evidence for such behavior in AN, in which restrictive intake has been related to dorsal frontostriatal systems. Other neural and neurocognitive data provide mixed findings, some of which suggest disturbances in habit systems in AN. There are compelling behavioral and neural data to suggest that habit systems may underlie the persistence of AN. The habit model needs further research, via more direct behavioral hypothesis testing and probes of the development of habitual behavior. Investigation of the habit-centered model of AN may open avenues for the development of novel treatments.