Set-shifting ability across the spectrum of eating disorders and in overweight and obesity: a systematic review and meta-analysis

The relationship between cognitive phenotypes of compulsivity and impulsivity and clinical variables in obsessive-compulsive disorder: A systematic review and Meta-analysis

BACKGROUND

This systematic review and meta-analysis explored the relationship between cognitive phenotypes of compulsivity and impulsivity and clinical variables in obsessive-compulsive disorder (OCD).

METHODS

We searched Pubmed, Scopus, Cochrane Library and PsychINFO databases until February 2023 for studies comparing patients with OCD and healthy controls on cognitive tests of compulsivity and impulsivity. The study followed PRISMA guidelines and was pre-registered on PROSPERO (CRD42021299017).

RESULTS

Meta-analyses of 112 studies involving 8313 participants (4289 patients with OCD and 4024 healthy controls) identified significant impairments in compulsivity (g = -0.58, [95%CI -0.68, -0.47]; k = 76) and impulsivity (g = -0.48, [95%CI -0.57, -0.38]; k = 63); no significant difference between impairments. Medication use and comorbid psychiatric disorders were not significantly related to impairments. No associations were revealed with OCD severity, depression/anxiety, or illness duration.

CONCLUSION

Cognitive phenotypes of compulsivity and impulsivity in patients with OCD appear to be orthogonal to clinical variables, including severity of OCD symptomatology. Their clinical impact is poorly understood and may require different clinical assessment tools and interventions.

Disentangling cognitive flexibility: a model-based assessment of women with anorexia nervosa

Cognitive flexibility (CF) has been proposed as a potential trait marker in anorexia nervosa (AN), although findings have been inconsistent. To address this inconsistency, we applied a model that distinguishes between three subtypes of CF: task switching, switching sets, and stimulus-response mapping, which we then assessed using a paradigm-based task battery. The aim of the study was to investigate how AN is associated with these three CF subtypes. Thirty-three women with AN and 37 age- and education-matched controls performed a battery of computerized cognitive tasks to assess the three CF subtypes. Compared to the control group, individuals with AN exhibited poorer performance on the task switching and switching sets subtypes, as measured by response time switch cost, but not on the stimulus-response mapping subtype. No differences were found between the groups in response accuracy. Furthermore, switching sets as compared to the task switching and stimulus-response mapping subtypes was found to better explain the differences between the groups. These findings indicate a domain-specific impairment in CF among patients with AN, reflecting deficits observed in subtypes related to the disorder's characteristics, particularly that associated with visual perception. Therefore, CF impairment in AN should not be viewed dichotomously, but rather as a relative impairment that varies depending on the specific CF subtype.

Sociodemographic correlates of parent and youth-reported eating disorder symptoms in the Adolescent Brain Cognitive Development Study

PURPOSE

Eating Disorders (EDs) often start in adolescence, though ED-related concerns in diverse youth samples remain understudied. We leveraged data from the Adolescent Brain Cognitive Development (ABCD) Study to identify the prevalence of parent- and youth-reported ED symptoms and their sociodemographic characteristics.

METHODS

Data were drawn from baseline (ages 9-11 years, n=11,868) and 2-year follow-up (ages 11-14 years; n=10,908) from the ABCD Study. A tetrachoric factor analysis summarized clusters of ED symptoms, which were compared between parent and youth reports and across sociodemographic variables.

RESULTS

Three factors emerged reflecting "weight distress", "weight control", and "binge eating" (prevalence range: 1.5-7.3%). Symptoms loaded onto similar factors between reporters. Rates of symptom endorsement were similar between sexes, with disproportionately higher endorsement rates for youth who self-identified as sexual minority, Hispanic, Black, or Mixed race participants, and those from a disadvantaged socioeconomic background, compared to the reference ABCD sample. Youth and parent reports at 2-year showed ~12% overlap.

CONCLUSIONS

ED-related concerns among historically understudied racial and sexual minority groups call for greater attention to the detection and treatment of these symptoms in these groups. Applying a transdiagnostic approach to ED symptoms can inform effective detection and intervention efforts.

The importance of improving cognitive flexibility in adolescents with anorexia nervosa: The case for cognitive remediation therapy

OBJECTIVE

Inefficiencies in executive functioning (EF), more specifically cognitive flexibility and an overly detailed processing style, are frequently observed in individuals with Anorexia Nervosa (AN) and have been identified as potential targets in treatment. Cognitive Remediation Therapy (CRT) is an adjunctive treatment approach specifically designed to have a positive impact on EF. Mainly evaluated in adults, CRT has been criticized for its perceived ineffectiveness in promoting weight restoration or directly reducing eating disorder symptoms.

METHOD

We argue that we need to refocus our conceptual framework for using CRT as an adjunctive treatment and specifically explore its potential benefit in adolescents.

RESULTS

Adolescence is a critical window for EF development during which CRT has the potential to have the most impact. While it may not specifically ameliorate eating disorder symptoms and directly improve weight gain, CRT may mitigate the impact of malnutrition on adolescent brain development, reduce attrition rates in treatment, and improve cognitive flexibility and (indirectly) other maintaining factors, thereby improving global functioning.

DISCUSSION

More research needs to be done to understand the development of EF in adolescents with AN and how best to employ CRT as an adjunctive treatment to support development and target maintaining factors. The current article broadly reviews findings on executive functioning inefficiencies in adolescents with AN and discusses the purpose and role of CRT in treating AN. Finally, we highlight key critiques of using CRT and pose questions for future research.

PUBLIC SIGNIFICANCE

Treatments targeting executive functioning in adolescents with AN are limited. We need to better understand how CRT can benefit adolescents in treatment. Increasing treatment options, including adjunctive treatments, is necessary to reduce the long-term impact of AN.

Psilocybin restrains activity-based anorexia in female rats by enhancing cognitive flexibility: contributions from 5-HT1A and 5-HT2A receptor mechanisms

Psilocybin has shown promise for alleviating symptoms of depression and is currently in clinical trials for the treatment of anorexia nervosa (AN), a condition that is characterised by persistent cognitive inflexibility. Considering that enhanced cognitive flexibility after psilocybin treatment is reported to occur in individuals with depression, it is plausible that psilocybin could improve symptoms of AN by breaking down cognitive inflexibility. A mechanistic understanding of the actions of psilocybin is required to tailor the clinical application of psilocybin to individuals most likely to respond with positive outcomes. This can only be achieved using incisive neurobiological approaches in animal models. Here, we use the activity-based anorexia (ABA) rat model and comprehensively assess aspects of reinforcement learning to show that psilocybin (post-acutely) improves body weight maintenance in female rats and facilitates cognitive flexibility, specifically via improved adaptation to the initial reversal of reward contingencies. Further, we reveal the involvement of signalling through the serotonin (5-HT) 1 A and 5-HT2A receptor subtypes in specific aspects of learning, demonstrating that 5-HT1A antagonism negates the cognitive enhancing effects of psilocybin. Moreover, we show that psilocybin elicits a transient increase and decrease in cortical transcription of these receptors (Htr2a and Htr1a, respectively), and a further reduction in the abundance of Htr2a transcripts in rats exposed to the ABA model. Together, these findings support the hypothesis that psilocybin could ameliorate cognitive inflexibility in the context of AN and highlight a need to better understand the therapeutic mechanisms independent of 5-HT2A receptor binding.

Weak central coherence, cognitive rigidity and disordered eating in a community sample

Recent evidence has highlighted that a moderate degree of disordered eating has become the norm among the general population. While previous research has demonstrated that individuals with eating disorders exhibit heightened weak central coherence (i.e., attention to detail) and cognitive rigidity, and this plays a key role in the development and maintenance of the disorders, less is known about the relationship between disordered eating and these cognitive styles in subclinical community samples. A community sample of females completed self-report measures of weak central coherence, cognitive rigidity and eating disorder pathology. Unlike previous studies in the area, we first excluded participants with a diagnosis of eating disorder and then confined the analyses to those without clinically significant disordered eating. In line with the clinical literature, we found both cognitive rigidity and weak central coherence to correlate with severity and frequency of disordered eating behaviours and cognitions, suggesting the relationship also exists in subclinical samples. If replicated and expanded upon, these findings may bear important implications for the prevention and early identification of disordered eating in the community.

The Journey of Engaging With Web-Based Self-Harm and Suicide Content: Longitudinal Qualitative Study

BACKGROUND

Self-harm and suicide are major public health concerns worldwide, with attention focused on the web environment as a helpful or harmful influence. Longitudinal research on self-harm and suicide-related internet use is limited, highlighting a paucity of evidence on long-term patterns and effects of engaging with such content.

OBJECTIVE

This study explores the experiences of people engaging with self-harm or suicide content over a 6-month period.

METHODS

This study used qualitative and digital ethnographic methods longitudinally, including one-to-one interviews at 3 time points to explore individual narratives. A trajectory analysis approach involving 4 steps was used to interpret the data.

RESULTS

The findings from 14 participants established the web-based journey of people who engage with self-harm or suicide content. In total, 5 themes were identified: initial interactions with self-harm or suicide content, changes in what self-harm or suicide content people engage with and where, changes in experiences of self-harm or suicide behaviors associated with web-based self-harm or suicide content engagement, the disengagement-reengagement cycle, and future perspectives on web-based self-harm or suicide content engagement. Initial engagements were driven by participants seeking help, often when offline support had been unavailable. Some participants' exposure to self-harm and suicide content led to their own self-harm and suicide behaviors, with varying patterns of change over time. Notably, disengagement from web-based self-harm and suicide spaces served as a protective measure for all participants, but the pull of familiar content resulted in only brief periods of disconnection. Participants also expressed future intentions to continue returning to these self-harm and suicide web-based spaces, acknowledging the nonlinear nature of their own recovery journey and aiming to support others in the community. Within the themes identified in this study, narratives revealed that participants' behavior was shaped by cognitive flexibility and rigidity, metacognitive abilities, and digital expertise. Opportunities for behavior change arose during periods of cognitive flexibility prompted by life events, stressors, and shifts in mental health. Participants sought diverse and potentially harmful content during challenging times but moved toward recovery-oriented engagements in positive circumstances. Metacognitive and digital efficacy skills also played a pivotal role in participants' control of web-based interactions, enabling more effective management of content or platforms or sites that posed potential harms.

CONCLUSIONS

This study demonstrated the complexity of web-based interactions, with beneficial and harmful content intertwined. Participants who demonstrated metacognition and digital efficacy had better control over web-based engagements. Some attributed these skills to study processes, including taking part in reflective diaries, showing the potential of upskilling users. This study also highlighted how participants remained vulnerable by engaging with familiar web-based spaces, emphasizing the responsibility of web-based industry leaders to develop tools that empower users to enhance their web-based safety.

A new network analysis model in anorexia nervosa patients based on self-reported eating disorder symptoms, psychological distress, and cognitive flexibility

OBJECTIVES

Cognitive flexibility and psychological distress, such as depression and anxiety, have been implicated in the aetiology of Anorexia Nervosa (AN). Despite the known associations between eating disorder (ED) symptoms, depression, anxiety, and cognitive flexibility, the specific pathways that connect these constructs are unclear. We therefore used network analysis to examine the relationship between these symptoms in an AN sample.

METHODS

One hundred and ninety-three treatment-seeking individuals diagnosed with AN (95.6% female, M = 26.89 [SD = 9.45] years old) completed self-report measures assessing depression, anxiety, cognitive flexibility, and ED symptoms. To determine each symptom's influence in the network, we calculated the expected influence.

RESULTS

The two relationships with the greatest edges were those between (1) weight/shape concerns and eating/dietary restraint and (2) weight/shape concerns and psychological distress (a measure that combined depression and anxiety). Cognitive flexibility was not connected to weight/shape concerns but had negative partial associations with eating concerns/dietary restraint and psychological distress. There was also a slight, non-zero connection between eating concerns/dietary restraint and psychological distress.

CONCLUSIONS

The findings underscore the importance of weight/shape, eating/dietary concerns, and psychological distress in the AN network and suggest that addressing cognitive flexibility may be a useful target for eating concerns/dietary restraint and psychological distress. Future studies assessing the longitudinal course of psychopathology within the AN network structure may help in identifying whether specific symptoms function as risk factors or maintaining factors for this co-occurrence.

Factor structure of the Eating Disorder Flexibility Index in U.S. nonclinical collegiate and clinical adolescent samples

Cognitive and behavioral inflexibility are transdiagnostic maintaining mechanisms of varied psychopathologies, including eating disorders (ED). The Eating Disorder Flexibility Index (EDFLIX) is the only psychometrically validated self-report measure of general and ED-specific flexibility in the published literature. The EDFLIX was originally developed in Scandinavian adult clinical and healthy control samples but is increasingly used in its English version in other populations, including adolescent and nonclinical samples, raising questions about its validity and reliability in diverse groups. This study examined the factor structure of the previously published English EDFLIX in undergraduates (n = 578, 57.6 % female, 50.2 % White). Parallel and exploratory factor analysis suggested the EDFLIX may comprise two or three underlying factors. However, follow-up confirmatory factor analyses from nonclinical student and clinical ED-diagnosed (n = 69, 87.0 % female, 91.3 % White) samples did not support either model. Further, EDFLIX scores did not correlate with established neuropsychological measures of cognitive flexibility typically used in prior research on flexibility in EDs. Findings suggest the EDFLIX has poor psychometric properties in certain groups and may not capture underlying aspects of flexibility as previously proposed. Future research should explore alternative versions of the EDFLIX along with its psychometric properties across various samples.

From gut microbiota to brain: implications on binge eating disorders

The prevalence of eating disorders has been increasing over the last 50 years. Binge eating disorder (BED) and bulimia nervosa (BN) are two typical disabling, costly and life-threatening eating disorders that substantially compromise the physical well-being of individuals while undermining their psychological functioning. The distressing and recurrent episodes of binge eating are commonly observed in both BED and BN; however, they diverge as BN often involves the adoption of inappropriate compensatory behaviors aimed at averting weight gain. Normal eating behavior is coordinated by a well-regulated trade-off between intestinal and central ingestive mechanism. Conversely, despite the fact that the etiology of BED and BN remains incompletely resolved, emerging evidence corroborates the notion that dysbiosis of gastrointestinal microbiome and its metabolites, alteration of gut-brain axis, as well as malfunctioning central circuitry regulating motivation, execution and reward all contribute to the pathology of binge eating. In this review, we aim to outline the current state of knowledge pertaining to the potential mechanisms through which each component of the gut-brain axis participates in binge eating behaviors, and provide insight for the development of microbiome-based therapeutic interventions that hold promise in ameliorating patients afflicted with binge eating disorders.

Impulsivity and compulsivity in gambling disorder and bulimic spectrum eating disorders: Analysis of neuropsychological profiles and sex differences

BACKGROUND

Gambling disorder (GD) and bulimic spectrum eating disorders (BSDs) not only share numerous psychopathological, neurobiological, and comorbidity features but also are distinguished by the presence of inappropriate behaviours related to impulsivity and compulsivity. This study aimed to emphasise the differences and similarities in the main impulsivity and compulsivity features between GD and BSD patients, and to analyse the potential influence of sex in these domains.

METHODS

Using self-reported and neurocognitive measures, we assessed different impulsive-compulsive components in a sample of 218 female and male patients (59 with BSD and 159 with GD) and 150 healthy controls.

RESULTS

We observed that GD and BSDs exhibited elevated levels of impulsivity and compulsivity in all the dimensions compared to healthy controls. Moreover, these disorders showed differences in several personality traits, such as high novelty seeking in GD, and low persistence and high harm avoidance in BSDs. In addition, patients with BSDs also displayed a trend towards greater impulsive choice than GD patients. Regarding sex effects, GD women presented higher overall impulsivity and compulsivity than GD men. Nevertheless, no sex differences were found in BSDs.

CONCLUSIONS

Clinical interventions should consider these deficits to enhance their effectiveness, including adjunctive treatment to target these difficulties. Our findings also provide support to the relevance of sex in GD, which should also be considered in clinical interventions.

Childhood hyperactivity, eating behaviours, and executive functions: Their association with the development of eating-disorder symptoms in adolescence

BACKGROUND

Cross-sectional studies have shown that hyperactivity and impaired executive functioning are associated with symptoms of eating disorders in adolescence and adulthood. Whether hyperactivity and executive functions in early life can prospectively predict the emergence of eating disorder symptoms in adolescence remains unknown. The present study relies on a longitudinal design to investigate how hyperactivity at age 3, eating behaviours at age 3.5 and cognition at ages 3-6 were associated with the development of eating-disorder symptoms from 12 to 20 years old.

METHODS

Using archival data collected since 1997 from the Quebec Longitudinal Study of Child Development cohort (N = 2, 223), we used Latent Curve Models to analyse predictors of youth's trajectories of eating-disorder symptoms at four timepoints.

RESULTS

A quadratic (curvilinear) trajectory of eating-disorder symptoms was found to be most representative of the data. Higher hyperactivity at age 3 was associated with higher levels of eating-disorder symptoms at age 12, and this association was partially mediated by higher levels of overeating and cognitive inflexibility in childhood. Cognitive inflexibility in childhood also mediated the association between hyperactivity at age 3 and increases in eating-disorder symptoms during adolescence. Furthermore, working memory was indirectly related to eating-disorder symptoms via the mediational role of cognitive flexibility.

CONCLUSIONS

Hyperactivity, overeating, cognitive inflexibility, and working memory early in life might precede the onset of eating-disorder symptoms in adolescence. Early behavioural and cognitive screening may help to identify children who are most at risk for eating disorders. This, in turn, could guide preventive interventions.

Cognitive flexibility and DSM-5 severity criteria for eating disorders: assessing drive for thinness and duration of illness as alternative severity variables

BACKGROUND

The severity criteria for eating disorders (EDs) proposed in the DSM-5 have been established without sufficient empirical support. Drive for thinness (DT) and duration of illness have been proposed as two alternative severity measures, however their empirical evidence is also limited. To date, no research has assessed the validity of current eating disorder (ED) severity criteria regarding cognitive flexibility factors. Cognitive flexibility is often impaired in EDs, becoming a possible severity symptom. The current study assessed for the first time (1) whether the severity indexes for EDs proposed in the DSM-5 were associated with deficits in cognitive flexibility and, (2) whether drive for thinness and illness duration, acted as an alternative, more meaningful severity indices for deficiencies in cognitive flexibility.

METHODS

Participants were 161 patients diagnosed with an ED, who were categorized according to DSM-5 severity categories, DT and duration of illness. Discriminative capacity of each classification was assessed for cognitive flexibility measured by Wisconsin card sorting test (WCST).

RESULTS

The findings for the DSM-5 classification comprised: (a) In the anorexia nervosa (AN) group, patients with moderate severity showed better scores in WCST than patients with mild and severe/extreme severity. Also, patients with moderate severity showed lower percentage of cognitive flexibility deficits than the other two severity categories; (b) For the binge spectrum disorders (BSD) group, the patients with mild severity showed a higher percentage of cognitive flexibility deficits than did the moderate and severe/extreme categories. When assessing the alternative severity index of DT, no differences were found in cognitive flexibility in any of the groups. Regarding illness duration, in the AN group the task performance of the patients with longer illness duration was worse than the performance of the short duration group and, in the BSD group, patients with longer duration also showed more deficits in cognitive flexibility than the patients with shorter duration of illness.

CONCLUSIONS

Our findings point out the limitations of the DSM-5 severity criteria to categorize cognitive flexibility in EDs and support illness duration as an alternative severity approach for EDs.

Exploring the role of autistic traits and eating disorder psychopathology on mentalising ability in the general population

BACKGROUND

This study evaluated the role of overlapping traits and characteristics related to autism spectrum disorder (autism) and anorexia nervosa (AN) in the general population, and the impact of these traits on mentalising ability.

METHODS

A sample of young adults (N = 306), aged 18-25 years, was recruited to complete an online study that consisted of 4 measures: the Autism-Spectrum Quotient, Eating Disorder Examination Questionnaire, the Mentalization Scale, and the Reading the Mind in the Eyes task.

RESULTS

Higher levels of autistic traits, particularly difficulty with attention switching, were associated with increased eating disorder psychopathology. Overall, autistic traits and eating disorder psychopathology were related among females, but not males. Difficulty with attention switching, however, was related to eating disorder psychopathology among both females and males. Autistic traits also appear to have a greater role in mentalising ability than does eating disorder psychopathology.

CONCLUSION

The role of attention switching in overlapping traits of autism and eating disorder psychopathology needs to be more comprehensively evaluated by future research, as does the role of biological sex. Expanded knowledge in this field will help to better understand and evaluate symptoms at presentation, leading to clearer diagnoses and potentially better treatment outcomes.

Dysfunctional decision-making in binge-eating disorder: A meta-analysis and systematic review

Binge-Eating Disorder (BED) involves anticipatory craving and urges, subjective loss-of-control during binge-eating episodes, and post-feeding psychological distress and guilt. Evidence indicates neurocognitive dysfunctions contribute to BED onset, maintenance, and treatment response. However, an integrated understanding of how cognitive processes underpin BED symptomology is lacking. We utilised a multi-stage decision-making model defining ten cognitive processes underpinning Preference Formation, Choice Implementation, Feedback Processing, and Flexibility/Shifting, to comprehensively review research published since 2013. We used preregistered PICOS criteria to assess 1966 articles identified from PubMed, PsycInfo, and Scopus database searches. This yielded 50 studies reporting behavioural cognitive tasks outcomes, comparing individuals with BED to controls with normal and higher weight. Meta-analyses revealed a unique profile of cognitive dysfunctions that spanned all decision-making stages. Significant deficits were evident in Uncertainty Evaluation, Attentional Inhibition, Choice Consistency, and Cognitive Flexibility/Set-shifting. We propose a novel model of dysfunctional decision-making processes in BED and describe their role in binge-eating behaviour. We further highlight the potential for cognitive interventions to target these processes and address the significant treatment gap in BED.

Measuring cognitive flexibility in anorexia nervosa: Wisconsin Card Sorting Test versus cued task-switching

PURPOSE

The Wisconsin Card Sorting Test (WCST) is the most common measure of cognitive flexibility in anorexia nervosa (AN), but task-switching paradigms are beginning to be utilized. The current study directly compared performance on a cued task-switching measure and the WCST to evaluate their association in participants with a lifetime diagnosis of AN, and to assess which measure is more strongly associated with clinical symptoms.

METHODS

Forty-five women with a lifetime diagnosis of AN completed the WCST, cued color-shape task-switching paradigm, Anti-saccade Keyboard Task, Running Memory Span, Eating Disorder Examination Questionnaire, Depression Anxiety Stress Scales short form and Eating Disorder Flexibility Index.

RESULTS

There was no evidence of a significant association between WCST perseverative errors and cued task-switching switch costs. Results suggest lower working memory capacity is a determinant of higher perseverative error rate. When controlling for mood variables, neither cognitive flexibility measure was a significant independent predictor of symptom severity.

CONCLUSIONS

Results provide support for previous suggestions that WCST perseverative errors could occur due to difficulties with working memory, sensitivity to feedback, and issues with concept formation. Cued task-switching paradigms may provide a useful measure of cognitive flexibility for future eating disorders research by reducing task-specific confounds.

LEVEL OF EVIDENCE

Level III Case-control analytic study.

Impaired belief updating and devaluation in adult women with bulimia nervosa

Recent models of bulimia nervosa (BN) propose that binge-purge episodes ultimately become automatic in response to cues and insensitive to negative outcomes. Here, we examined whether women with BN show alterations in instrumental learning and devaluation sensitivity using traditional and computational modeling analyses of behavioral data. Adult women with BN (n = 30) and group-matched healthy controls (n = 31) completed a task in which they first learned stimulus-response-outcome associations. Then, participants were required to repeatedly adjust their responses in a "baseline test", when different sets of stimuli were explicitly devalued, and in a "slips-of-action test", when outcomes instead of stimuli were devalued. The BN group showed intact behavioral sensitivity to outcome devaluation during the slips-of-action test, but showed difficulty overriding previously learned stimulus-response associations on the baseline test. Results from a Bayesian learner model indicated that this impaired performance could be accounted for by a slower pace of belief updating when a new set of previously learned responses had to be inhibited (p = 0.036). Worse performance and a slower belief update in the baseline test were each associated with more frequent binge eating (p = 0.012) and purging (p = 0.002). Our findings suggest that BN diagnosis and severity are associated with deficits in flexibly updating beliefs to withhold previously learned responses to cues. Additional research is needed to determine whether this impaired ability to adjust behavior is responsible for maintaining automatic and persistent binge eating and purging in response to internal and environmental cues.

Ketamine and Zinc: Treatment of Anorexia Nervosa Via Dual NMDA Receptor Modulation

Anorexia nervosa is a disorder associated with serious adverse health outcomes, for which there is currently considerable treatment ineffectiveness. Characterised by restrictive eating behaviours, distorted body image perceptions and excessive physical activity, there is growing recognition anorexia nervosa is associated with underlying dysfunction in excitatory and inhibitory neurometabolite metabolism and signalling. This narrative review critically explores the role of N-methyl-D-aspartate receptor-mediated excitatory and inhibitory neurometabolite dysfunction in anorexia nervosa and its associated biomarkers. The existing magnetic resonance spectroscopy literature in anorexia nervosa is reviewed and we outline the brain region-specific neurometabolite changes that have been reported and their connection to anorexia nervosa psychopathology. Considering the proposed role of dysfunctional neurotransmission in anorexia nervosa, the potential utility of zinc supplementation and sub-anaesthetic doses of ketamine in normalising this is discussed with reference to previous research in anorexia nervosa and other neuropsychiatric conditions. The rationale for future research to investigate the combined use of low-dose ketamine and zinc supplementation to potentially extend the therapeutic benefits in anorexia nervosa is subsequently explored and promising biological markers for assessing and potentially predicting treatment response are outlined.

Altered Reinforcement Learning from Reward and Punishment in Anorexia Nervosa: Evidence from Computational Modeling

OBJECTIVES

Anorexia nervosa (AN) is associated with altered sensitivity to reward and punishment. Few studies have investigated whether this results in aberrant learning. The ability to learn from rewarding and aversive experiences is essential for flexibly adapting to changing environments, yet individuals with AN tend to demonstrate cognitive inflexibility, difficulty set-shifting and altered decision-making. Deficient reinforcement learning may contribute to repeated engagement in maladaptive behavior.

METHODS

This study investigated learning in AN using a probabilistic associative learning task that separated learning of stimuli via reward from learning via punishment. Forty-two individuals with Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 restricting-type AN were compared to 38 healthy controls (HCs). We applied computational models of reinforcement learning to assess group differences in learning, thought to be driven by violations in expectations, or prediction errors (PEs). Linear regression analyses examined whether learning parameters predicted BMI at discharge.

RESULTS

AN had lower learning rates than HC following both positive and negative PE (p < .02), and were less likely to exploit what they had learned. Negative PE on punishment trials predicted lower discharge BMI (p < .001), suggesting individuals with more negative expectancies about avoiding punishment had the poorest outcome.

CONCLUSIONS

This is the first study to show lower rates of learning in AN following both positive and negative outcomes, with worse punishment learning predicting less weight gain. An inability to modify expectations about avoiding punishment might explain persistence of restricted eating despite negative consequences, and suggests that treatments that modify negative expectancy might be effective in reducing food avoidance in AN.

Orthorexia nervosa and executive dysfunction: symptomatology is related to difficulties with behavioral regulation

PURPOSE

This research explored whether orthorexia nervosa is associated with deficits in executive function.

METHODS

A non-clinical sample of participants (n = 405; 80% women, 53% white, mean age = 24, mean body mass index = 25) completed the Orthorexia Nervosa Inventory (ONI) and the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A).

RESULTS

ONI scores were weakly to moderately correlated with all BRIEF-A scales (p < 0.001 for eight scales, p < 0.05 for one scale), exhibiting the greatest correlations with the scales assessing behavioral regulation: Emotional Control (r = 0.34), Inhibition (r = 0.30), Set Shifting (r = 0.25), and Self-Monitoring (r = 0.28). Hierarchical regression analyses revealed that eight of these nine relationships remained significant (p < 0.001 for five scales including all behavioral regulation scales, p < 0.01 for two scales, p < 0.05 for one scale) after controlling for demographic variables (e.g., gender, body mass index, age, education level) and diagnoses of an eating disorder, obsessive-compulsive disorder, attention deficit/hyperactivity disorder, autism, and learning disability.

CONCLUSION

These findings suggest that, despite unique manifestations, orthorexia and anorexia may possess an overlapping neuropsychological profile marked by deficits in executive function, which may negatively impact daily life.

LEVEL OF EVIDENCE

Level V, descriptive cross-sectional study.

An exploratory examination of executive functioning as an outcome, moderator, and predictor in outpatient treatment for adults with anorexia nervosa

OBJECTIVE

People with anorexia nervosa often exhibit inefficiencies in executive functioning (central coherence and set shifting) that may negatively impact on treatment outcomes. It is unclear from previous research whether these inefficiencies can change over treatment. We aimed to (1) investigate whether executive functioning can improve over treatment, (2) determine whether baseline executive functioning moderates treatment outcome, and (3) examine whether baseline executive functioning predicts early change (i.e., increase in body mass index over the first 13 weeks of treatment) or remission.

METHOD

We conducted linear mixed model and logistic regression analyses on data from the Strong Without Anorexia Nervosa trial (Byrne et al. in Psychol Med 47:2823-2833, 2017). This study was a randomised controlled trial of three outpatient treatments for people with anorexia nervosa: Enhanced Cognitive Behavioural Therapy, Maudsley Model Anorexia Nervosa Treatment for Adults, and Specialist Supportive Clinical Management.

RESULTS

While set shifting clearly improved from baseline to end of treatment, the results for central coherence were less clear cut. People with low baseline central coherence had more rapid reductions in eating disorder psychopathology and clinical impairment than those with high baseline central coherence. Baseline executive functioning did not predict early change or remission.

DISCUSSION

The detail-focused thinking style commonly observed among people with anorexia nervosa may aid treatment outcomes. Future research that is more adequately powered should replicate this study and examine whether the same pattern of results is observed among people with non-underweight eating disorders.

Interactions between emotion regulation and everyday flexibility in anorexia nervosa: Preliminary evidence of associations with clinical outcomes

The current study explored interactions between emotion regulation (ER) and cognitive-behavioral flexibility in everyday life in individuals with anorexia nervosa (AN). Participants were 97 female adults with current (57%) or past (43%) full or partial AN syndrome diagnosis. Participants completed the Difficulties with Emotion Regulation Scale, Emotion Regulation Questionnaire, Eating Disorder Flexibility Index, Eating Disorder Examination Questionnaire and Depression Anxiety Stress Scale short form. Lower flexibility was a strong independent predictor of more severe ED-related cognitions and higher frequency of compensatory behaviors beyond individual differences in emotion regulation and mood. ER measures did not predict clinical characteristics. However, two interactions between flexibility and ER measures were observed which suggested there was a stronger association between greater flexibility and higher BMI for individuals with either higher levels of cognitive reappraisal use, or higher levels of global ER difficulties. Interactions between flexibility and emotion regulation provide evidence that co-occurring difficulties may impact clinical outcomes in AN.

Evaluation of Web-Based Health Information From the Perspective of Women With Eating Disorders: Thematic Analysis

Background

Users with experience of eating disorders use the internet as a source of information, whether for prorecovery activities (such as web-based treatment, looking for information, support, and sharing) or activities that promote eating disorder behavior as a desirable lifestyle choice (such as pro–eating disorder communities and reading and creating pro–eating disorder posts). Their assessment of web-based eating disorder–related information is crucial for understanding the context of the illness and for health professionals and their web-based interventions.

Objective

This study aimed to understand the criteria young women with the experience of eating disorders use in evaluating eating disorder–related web-based information and what eating disorder–related characteristics of these women are involved in their evaluation.

Methods

We analyzed 30 semistructured individual interviews with Czech women aged 16 to 28 years with past or present eating disorder experience using a qualitative approach. Thematic analysis was adopted as an analytical tool.

Results

The specifics of eating disorder phases (the disorder stage and the treatment process) emerged as important aspects in the process of information assessment. Other specific characteristics of respondents (eg, motivation, abilities, and resources) addressed how the respondents arrived at certain web-based information and how they evaluated it. In addition, the respondents described some content cues as features of information (eg, novelty and social information pooling). Another finding is that other users’ attitudes, experiences, activities, and personal features are involved in the information evaluation of these users and the information presented by them. Finally, the respondents evaluated the websites’ visual look and graphic components.

Conclusions

This study shows that web-based information evaluation reported by women with experience of eating disorders is a complex process. The assessment is influenced by current personal characteristics related to the illness (mainly the motivation for maintaining or curing the eating disorder) using cues associated with information content, other users, and website look. The study findings have important implications for health professionals, who should ask their clients questions about web-based communities and their needs to understand what information and sources they choose.

Everyday flexibility and functional milestones in anorexia nervosa: survey results from a mixed community sample

PURPOSE

This study examined the relationship between self-reported cognitive-behavioral flexibility scores on the Eating Disorder Flexibility Index (EDFLIX) and objective social and occupational functional milestones in participants with a lifetime diagnosis of anorexia nervosa (AN). The Work and Social Adjustment Scale (WSAS) was included to compare objective and subjective measures.

METHODS

114 female adult participants with a current (53.5%) or past (46.5%) full or partial AN syndrome diagnosis completed an online survey which included functional milestone questions, the EDFLIX, WSAS, EDE-Q, and DASS-21.

RESULTS

Everyday flexibility scores were significantly associated with WSAS scores, but not functional milestones for the same domain. Lower flexibility was related to higher WSAS work impairment but was not associated with poor occupational outcomes. Lower flexibility was related to higher WSAS social impairment but was not associated with less frequent social contact with friends. Milestones across work, social and relationship areas were not significantly correlated, suggesting individuals have areas of strength and weakness across functional domains. In contrast, WSAS ratings indicated broad functional impairment.

CONCLUSION

Results from the milestones suggest self-reported cognitive-behavioral flexibility is not a strong determinant of everyday function. Results from the subjective WSAS function measure and the more objective functional milestones were not consistent. To obtain a more balanced assessment of everyday functioning in AN, both subjective and objective measures should be considered.

LEVEL OF EVIDENCE

Level III Case-control analytic study.

Neural Correlates of Executive Functioning in Anorexia Nervosa and Obsessive-Compulsive Disorder

Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) are commonly reported to co-occur and present with overlapping symptomatology. Executive functioning difficulties have been implicated in both mental health conditions. However, studies directly comparing these functions in AN and OCD are extremely limited. This review provides a synthesis of behavioral and neuroimaging research examining executive functioning in AN and OCD to bridge this gap in knowledge. We outline the similarities and differences in behavioral and neuroimaging findings between AN and OCD, focusing on set shifting, working memory, response inhibition, and response monitoring. This review aims to facilitate understanding of transdiagnostic correlates of executive functioning and highlights important considerations for future research. We also discuss the importance of examining both behavioral and neural markers when studying transdiagnostic correlates of executive functions.

Randomized controlled trial of cognitive remediation therapy in adolescent inpatients with anorexia nervosa: Neuropsychological outcomes

OBJECTIVE

Neuropsychological dysfunction exists in anorexia nervosa (AN). Cognitive Remediation Therapy (CRT), mainly evaluated in adults with AN, targets these impairments.

METHODS

Adolescent inpatients (age = 11-17 years) with AN were randomized to 5 weeks of either 10 sessions of individually delivered CRT or non-specific cognitive-training (NSCT). Co-primary outcomes included cognitive domain 'flexibility' [composite score of Wisconsin Card Sorting Test (WSCT) and Trail Making Test (TMT-4)] and 'central coherence' [composite score of Central Coherence Index (CCI) and Group Embedded Figures Test (GEFT)] at end of treatment (FU1). Secondary outcomes included individual test scores and self-reported everyday-life flexibility at FU1 and at 6-months post-treatment (FU2). Independent sample t-tests, Pearson chi-square-tests and mixed models for repeated measures (MMRM) analyses were conducted.

RESULTS

In 56 females (age = 15.1 ± 1.5 years), CRT was not superior to NSCT at FU1 regarding 'flexibility' (p = 0.768) or 'central coherence' (p = 0.354), nor at FU2 (p = 0.507; p = 0.624) (effect sizes = 0.02-0.26). Both groups improved over time in central coherence (CCI p = 0.001; GEFT p < 0.001), self-reported flexibility (p = 0.002) and WCST (p = 0.18), but not TMT-4 (p = 0.286). NSCT was superior to CRT regarding self-reported planning/organisation ability at FU1 (p < 0.001) and FU2 (p = 0.003).

CONCLUSIONS

CRT was not superior to NSCT in adolescent inpatients with AN. More randomized controlled studies are needed.

Olfactory capacity in anorexia nervosa: correlations with set-shifting ability

PURPOSE

The purpose of this study is to examine olfactory capacity in adults with anorexia nervosa (AN), in terms of odor identification and odor threshold and search for possible correlations between odor identification and cognitive flexibility in this population.

METHODS

Thirty-nine patients diagnosed with AN and 60 healthy participants, participated. Odor identification was assessed using the University Pennsylvania Smell Identification Test and a two alternative forced choice, ascending method with n-butanol was used to assess odor threshold. Cognitive flexibility was determined using the Intra/Extra-Dimensional Set-Shift test (IED), a subtest of the Cambridge Neuropsychological Test Automated Battery (CANTAB).

RESULTS

Patients with AN presented a poorer performance in odor identification compared with controls (p = 0.001). No differences were found in odor threshold, between the two groups. Patients with AN exhibited poor cognitive flexibility compared with controls (p = 0.003). A significant correlation between odor identification and cognitive flexibility was documented in AN (p = 0.01), but not in controls.

CONCLUSION

Our findings suggest that olfactory capacity is altered in AN: Qualitative characteristics of olfaction were affected in patients with AN (lower odor identification), while there was no difference in quantitative characteristics (odor threshold) compared with controls. Furthermore, odor identification in AN was correlated to cognitive flexibility.

LEVEL OF EVIDENCE

Level III: case-control analytic study.

Cognitive flexibility and attention to detail in adolescents and adults with severe forms of anorexia nervosa

OBJECTIVE

To determine if adolescents and adults diagnosed with anorexia nervosa differ in their levels of cognitive flexibility and attention to detail independently of potential confounds.

METHOD

Sixty-two adolescents and 54 adults were assessed while receiving inpatient treatment and completed the following self-reports: Eating Disorders Examination Questionnaire, Maudsley Obsessive Compulsive Inventory and Hospital Anxiety and Depression scale. Performance-based evaluations included the Wisconsin Card Sorting Test Computerised Version, the Comprehensive Trail Making Test, the Brixton Spatial Anticipation Test, the Rey Complex Figure and the Group Embedded Figures Test.

RESULTS

Comparisons of the adolescents and adults with anorexia nervosa revealed no significant differences for any of the neuropsychological test scores even after adjusting for potential confounding factors. Neither cognitive flexibility nor attention to detail were associated with level of eating disorder symptomatology, depression, anxiety or obsessive-compulsive symptomatology. Unlike age, illness duration was found weakly associated with perseverative errors Wisconsin Card Sorting Test and with the central coherence index of the Rey Complex Figure recall condition.

CONCLUSIONS

Set-shifting and central coherence performance were independent of age, clinical symptoms severity and emotional status. Additional studies on the relationship between the duration of anorexia nervosa and neuropsychological difficulties are needed.

Cognitive flexibility, central coherence, and quality of life in anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) has consistently been found to be associated with poor cognitive flexibility and central coherence. These two cognitive functions have been considered important maintenance factors in AN and are addressed by specific treatment approaches such as cognitive remediation therapy. While there is clear empirical evidence that difficulties in such cognitive functions are related to impaired daily functioning in schizophrenia and bipolar disorder, this potential association has received only little attention in AN research so far. Therefore, the aim of this study was to examine potential relationships between weak cognitive flexibility, central coherence, and poor quality of life (QoL) in AN.

METHODS

Cognitive flexibility and central coherence were measured by both neuropsychological (i.e., performance based) and self-report measures alongside with self-reported QoL in a sample of 138 adult patients with AN.

RESULTS

Self-report but not performance based measures of cognitive flexibility and central coherence were associated with QoL. Weaker cognitive flexibility and central coherence were correlated with poorer QoL. These associations were independent of comorbid depression. The link between weak central coherence and poor QoL was particularly strong in patients with the restricting subtype of AN. The link between cognitive flexibility and QoL, however, was independent of AN subtype.

CONCLUSIONS

Weak cognitive flexibility and central coherence are associated with low QoL in AN, especially in patients with the restrictive subtype. However, this relationship is dependent on the method of measurement, where self-report measures seem to be more relevant than performance based measures.

The role of cognitive flexibility in weight loss after severe obesity surgery-A retrospective study

Cognitive flexibility (CF) is a fundamental skill for behavioural regulation and adaptation during the weight-loss process. Research suggests that bariatric surgery (BS) candidates underperform consistently in the Wisconsin Card Sorting Test (WCST), which is a neuropsychological instrument that measures this ability. The current study explored the predictive value of preoperative performance in WCST CF dimensions alongside relevant psychological factors on weight loss after BS. The sample comprised 100 female patients who underwent BS in a public hospital in Lisbon, Portugal. We collected data using the WCST, the Hopkins Symptom Checklist-90-Revised (SCL-90-R), and the Binge Eating Scale (BES). Multiple linear regression (MLR) analyses were performed to obtain explanatory models of total weight loss at 12- and 24-postoperative months (TWL₁ and TWL₂ , respectively). MLR identified the number of preservative responses as a highly significant predictor of TWL₁ (p < 0.01)_, and the SCL-90-R obsession-compulsion and anxiety indices as highly significant predictors of TWL₁ and TWL₂ (p < 0.01). The number of preservative responses was a relevant predictor of weight loss at 12 months. Persisting in maladaptive cognitive strategies was associated with a lesser weight loss during the important period after BS that requires the adoption new lifestyle habits.

Volume and Connectivity Differences in Brain Networks Associated with Cognitive Constructs of Binge Eating

Bulimia nervosa (BN) and binge eating disorder (BED) are characterized by episodes of eating large amounts of food while experiencing a loss of control. Recent studies suggest that the underlying causes of BN/BED consist of a complex system of environmental cues, atypical processing of food stimuli, altered behavioral responding, and structural/functional brain differences compared with healthy controls (HC). In this narrative review, we provide an integrative account of the brain networks associated with the three cognitive constructs most integral to BN and BED, namely increased reward sensitivity, decreased cognitive control, and altered negative affect and stress responding. We show altered activity in BED/BN within several brain networks, specifically in the striatum, insula, prefrontal cortex (PFC) and orbitofrontal cortex (OFC), and cingulate gyrus. Numerous key nodes in these networks also differ in volume and connectivity compared with HC. We provide suggestions for how this integration may guide future research into these brain networks and cognitive constructs.

Cognitive and Experienced Flexibility in Patients With Anorexia Nervosa and Obsessive Compulsive Disorder

OBJECTIVE

Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) share a neuropsychological profile characterized by cognitive inflexibility as evident in set-shifting problems, and by strong detail focus. Clinically, both patient groups display a strong rigidity which may be explained by these neurocognitive difficulties. Cognitive inflexibility may hinder treatment uptake and help explain suboptimal treatment outcomes in both AN and OCD. This is the first study to compare clinical AN and OCD groups andto examine similarities and differences in cognitive flexibility. Specifically, this study aims to investigate neuropsychological outcomes and self-reported difficulties in both clinical groups and a control group, and explore associations between the different flexibility outcomes and illness.

METHOD

Two hundred participants (61 AN, 72 OCD and 67 HC) performed neuropsychological tasks on set-shifting abilities (Trail Making Task, Stroop color-word interference, Intradimensional-Extradimensional shift task), detail focus (Group Embedded Figures Test) and self-reported set-shifting abilities and attention to detail (DFlex).

RESULTS

Similarities between patient groups were found in terms of reduced set-shifting ability on the Trail Making Task and detail focus. Moreover, both patient groups self-reported more set-shifting problems but a less strong detail focus than HC, which in turn were not related to neuropsychological task outcomes in either of the groups. In both patient groups longer illness duration was associated to longer reaction times in the switching tasks and for both groups symptom severity was associated to higher experienced inflexibility and attention to detail.

CONCLUSION

Cognitive inflexibility processes are largely similar in patients with AN and OCD. Both patient groups report inflexibility, yet this is unrelated to neuropsychological outcomes. Illness duration seems to contribute to poorer set-shifting and higher illness severity is linked to more experienced inflexibility. Findings highlight the need for entangling different domains of cognitive flexibility and detail focus and examining self-report measures for a cohesive understanding of clinically relevant flexibility weaknesses in AN and OCD.

Executive function in obesity and anorexia nervosa: Opposite ends of a spectrum of disordered feeding behaviour?

Higher-order executive functions such as decision-making, cognitive flexibility and behavioural control are critical to adaptive success in all aspects of life, including the maintenance of a healthy body weight by regulating food intake. Performance on tasks designed to assess these aspects of cognition is impaired in individuals with obesity and anorexia nervosa (AN); conditions at either end of a spectrum of body weight disturbance. While the conceptualisation of obesity and AN as mirror images of each other makes some sense from a metabolic point of view, whether or not these conditions also reflect opposing states of executive function is less clear. Here, we review evidence from neurocognitive and neuroimaging studies to compare the direction and extent of executive dysfunction in subjects with obesity and AN and how these are underpinned by changes in structure and function of subregions of the prefrontal cortex (PFC). Both conditions of extreme body weight disturbance are associated with impaired decision-making and cognitive inflexibility, however, impulsive behaviour presents in opposing directions; obesity being associated with reduced behavioural control and AN being associated with elevated control over behaviour with respect to food and feeding. Accordingly, the subregions of the PFC that guide inhibitory control and valuation of action outcomes (dorsolateral prefrontal cortex and orbitofrontal cortex) show opposite patterns of activation in subjects with obesity compared to those with AN, whereas the subregions implicated in cognitive and behavioural flexibility (ventromedial prefrontal cortex and anterior cingulate cortex) show alterations in the same direction in both conditions but with differential extent of dysfunction. We synthesise these findings in the context of the utility of animal models of obesity and AN to interrogate the detail of the neurobiological contributions to cognition in patient populations and the utility of such detail to inform future treatment strategies that specifically target executive dysfunction.

Transdiagnostic Perspective of Impulsivity and Compulsivity in Obesity: From Cognitive Profile to Self-Reported Dimensions in Clinical Samples with and without Diabetes

Impulsive and compulsive behaviors have both been observed in individuals with obesity. The co-occurrence of obesity and type 2 diabetes (T2D) is more strongly associated with impulsivity, although there are no conclusive results yet. A multidimensional assessment of impulsivity and compulsivity was conducted in individuals with obesity in the absence or presence of T2D, compared with healthy, normal-weight individuals, with highly impulsive patients (gambling disorders), and with highly compulsive patients (anorexia nervosa). Decision making and novelty seeking were used to measure impulsivity, and cognitive flexibility and harm avoidance were used for compulsivity. For impulsivity, patients with obesity and T2D showed poorer decision-making ability compared with healthy individuals. For compulsivity, individuals with only obesity presented less cognitive flexibility and high harm avoidance; these dimensions were not associated with obesity with T2D. This study contributes to the knowledge of the mechanisms associated with diabetes and its association with impulsive–compulsive behaviors, confirming the hypothesis that patients with obesity and T2D would be characterized by higher levels of impulsivity.

Clinical factors predicting impaired executive functions in eating disorders: The role of illness duration

Poor performance in executive functions is observed in individuals with eating disorders (EDs). These impairments have usually been associated with the presence of comorbid psychopathology or with higher severity of EDs. However, few studies have explored the interaction between illness duration and deficits in executive functions. The present study investigates the association between ED duration and performance in decision-making, inhibitory control, and cognitive flexibility in the anorexia nervosa restrictive subtype (AN-R), bulimic/purging subtype (AN-BP), and binge spectrum disorders (BSDs) (namely, bulimia nervosa and binge eating disorder) among 116 women with EDs compared with 123 women healthy controls (HCs). Using cumulative survival analysis, we estimated the risk of deficits related to illness duration. Predictors of executive dysfunctions were assessed by regression analysis, including as potential predictors illness duration, severity of general psychopathology, and ED symptomatology. Results showed poor decision-making and cognitive flexibility in participants with EDs compared with HCs. ED duration was associated with poor inhibitory control in the AN-BP group and poor cognitive flexibility in the BSD group. The illness duration increased the risk of presenting early deficits in executive function. In decision-making and inhibitory control, the AN-R group showed the earliest deficits, whereas in cognitive flexibility it was the BSD group. ED duration predicted impaired cognitive flexibility in the BSD group and impaired inhibitory control in the AN-BP group, whereas the severity of general psychopathological symptoms was a predictor of impaired cognitive flexibility in individuals with AN-R. These results highlight the relevance of illness duration in executive dysfunctions in EDs.

How Does Fasting Affect Cognition? An Updated Systematic Review (2013-2020)

PURPOSE OF REVIEW

The goal of this review was to provide an update on the literature examining how voluntary, temporary abstention from eating impacts cognitive function.

RECENT FINDINGS

We evaluated peer-reviewed articles published between August 2013 and January 2021 that assessed adults, included a measure of cognitive functioning with neutral stimuli, and compared individuals in a fasted state to individuals in a fed state (either within- or between-subject designs). Nineteen articles (21 studies) met inclusion criteria. Sample sizes, fasting methods, and tasks varied across studies. Review of studies indicated that fasting was associated with deficits in cognitive functioning; few studies indicated a benefit in cognitive functioning following a single voluntary fast. The heterogeneity and rarity of available studies limits the conclusions that can be drawn. Several crucial psychosocial and sociodemographic moderators remain unexplored. Recommendations for future work are discussed.

The longitudinal relationship between set-shifting at 4 years of age and eating disorder related features at 9 years of age in the general pediatric population

BACKGROUND

Individuals with anorexia nervosa (AN) tend to have rigid thoughts and behaviors regarding their body weight, body image, and eating habits. While a diagnosis of AN implies severe levels of impairment, AN traits can vary on a continuum within the population. However, little is known about how early markers of AN relate to rigid thought patterns and to what extent cognitive rigidity is already present in early childhood. We examined the association of set-shifting abilities as a measure of cognitive flexibility in preadolescents with AN-related features.

METHODS

Participants included 3,987 children participating in the Generation R Study, a Dutch population-based birth cohort. Set-shifting abilities (mother report) were assessed at 4 years of age, body mass index (BMI) was determined at 4 and 9 years and restrictive eating patterns (mother report) and body image (child report) were assessed at 9 years.

RESULTS

Lower set-shifting abilities at 4 years were associated with a lower BMI (β = -.44, p = 2.2 × 10^-4 ) in girls, and more restrictive eating (β = 0.15, p = 2.7 × 10^-6 ) in both boys and girls at 9 years of age. Moreover, set-shifting at age 4 was not associated with body image at age 9.

CONCLUSION

These findings contribute to the idea that the association between set-shifting problems and AN-related features are present early in childhood, prior to the typical range of the onset of eating disorders (EDs). Longitudinal studies that capture the peak age for the development of EDs will be important to assess whether early cognitive inflexibility is an early marker of AN.

Are Sensitivity to Punishment, Sensitivity to Reward and Effortful Control Transdiagnostic Mechanisms Underlying the Eating Disorder/Obesity Spectrum?

Although it has been postulated that eating disorders (EDs) and obesity form part of a broad spectrum of eating- and weight-related disorders, this has not yet been tested empirically. In the present study, we investigated interindividual differences in sensitivity to punishment, sensitivity to reward, and effortful control along the ED/obesity spectrum in women. We used data on 286 patients with eating disorders (44.6% AN-R, 24.12% AN-BP, and 31.82% BN), 126 healthy controls, and 640 Class II/III obese bariatric patients (32.81% Class II and 67.19% Class III) with and without binge eating. Participants completed the behavioral inhibition and behavioral activation scales, as well as the effortful control scale, to assess sensitivity to punishment and reward and effortful control. Results showed that patients with EDs scored significantly higher on punishment sensitivity (anxiety) compared to healthy controls and Class II/III obese patients; the different groups did not differ significantly on reward sensitivity. Patients with binge eating or compensatory behaviors scored significantly lower on effortful control than patients without binge eating. Differences in temperamental profiles along the ED/obesity spectrum appear continuous and gradual rather than categorical. This implies that it may be meaningful to include emotion regulation and impulse regulation training in the treatment of both EDs and obesity.

Impulsivity and compulsivity in binge eating disorder: A systematic review of behavioral studies

BACKGROUND

Binge eating disorder (BED) often includes impulsive and compulsive behaviors related to eating behavior and food. Impulsivity and compulsivity generally may contribute to the etiology and maintenance of multiple psychiatric disorders including BED. This review aimed to identify and synthesize available behavioral studies of impulsivity and compulsivity among individuals with BED.

METHOD

A systematic search was performed focusing on BED and specific facets of impulsivity (rapid response and choice) and compulsivity (set-shifting, cognitive flexibility, and/or habit learning). All case-control studies comparing adults with either full-threshold or subthreshold BED to individuals with normal weight, overweight/obesity, or other eating disorders (e.g., bulimia nervosa) were included.

RESULTS

Thirty-two studies representing 29 unique samples met inclusion criteria. Increased choice impulsivity was observed among individuals with BED relative to individuals with normal weight. There were mixed findings and/or a lack of available evidence regarding rapid response impulsivity and compulsivity. The presence of between-group differences was not dependent on sample characteristics (e.g., full or sub threshold BED diagnosis, or treatment-seeking status). Heterogeneity relating to covariates, task methodologies, and power limited conclusions.

CONCLUSIONS

Literature supports a postive association between choice impulsivity and BED. More research is needed to determine if individuals with BED demonstrate elevated levels of either rapid response impulsivity or types of compulsivity. Careful selection of covariates and consideration of task methodologies and power would aid future research.

The Neuropsychological Profile of Severe and Enduring Anorexia Nervosa: A Systematic Review

Characteristics of Severe and Enduring Anorexia Nervosa (SE-AN) are being investigated to differentiate the patients experiencing SE-AN from those at earlier stages of the AN disease. The current systematic review was the first step in exploring neuropsychological functioning as a potentially identifying characteristic for long-term presentations. With a subgroup of AN patients reflecting a unique neuropsychological profile that is proportionate to the quantity of patients that go on to develop SE-AN, it was the aim of this review to assess neuropsychological functioning in the later stage of the disease. In accordance with PRISMA guidelines, a literature search was conducted using four electronic databases (PsycINFO, MEDLINE, Web of Science, and Scopus) for neuropsychological research on AN participants with a seven or more year illness duration. Datasets that met inclusion criteria were screened for SE-AN participants (N = 166) and neuropsychological data extracted together with potentially confounding variables and information required to conduct a quality assessment. In research investigating decision-making, participants with a SE-AN presentation demonstrated significantly lower functioning compared to healthy controls. There was conflicting evidence for differences in intellectual functioning and set-shifting abilities with no variability indicated in central coherence, memory, attention, reasoning, or processing speed. If findings from this preliminary analysis are confirmed through empirical research, implications include earlier identification of SE-AN patients and more effective treatment development.

The clinical obesity maintenance model: a structural equation model

PURPOSE

Theoretical research on the psychological underpinnings of weight management is limited. Recently, the clinical obesity maintenance model (COMM) proposed a theoretical conceptualisation of salient psychological and neuropsychological mechanisms maintaining weight management issues. The current study aimed to empirically test the COMM and elucidate the results in the context of recent empirical findings.

METHODS

Participants (N = 165) were recruited from university and community settings in Australia. The sample consisted of adults with normal weight (n = 41), overweight (n = 40), and obesity (n = 84). Participants completed self-report questionnaires and a brief neuropsychological test. Structural equation modelling was used to estimate the associations between the hypothesised variables of the COMM and evaluate the model fit.

RESULTS

Findings suggested acceptable to good model fit. Furthermore, several direct effects were found. First, cognitive flexibility directly affected eating habit strength. Second, eating habit strength directly affected eating beliefs. Third, eating beliefs directly affected emotion dysregulation. Fourth, emotion dysregulation directly affected depression and binge eating with depression partially mediating this relationship. Finally, depression directly affected binge eating.

CONCLUSION

This was the first study to empirically test the COMM. Overall, findings provide preliminary support for the COMM as a psychological model of weight management and highlight the underlying psychological and neuropsychological mechanisms that may contribute to weight management issues. As this study examined a simplified version of the COMM, future research should continue evaluating this model and consider incorporating these components into more holistic weight management models to improve long-term treatment outcomes.

LEVEL OF EVIDENCE

V, cross-sectional descriptive study.

Attentional and executive functions in children and adolescents with developmental coordination disorder and the influence of comorbid disorders: A systematic review of the literature

Developmental coordination disorder (DCD) is a neurodevelopmental disorder affecting primarily motor skills, but attentional and executive impairments are common in affected individuals. Moreover, the presence of neurodevelopmental comorbidities is frequent in this population, which certainly influences the cognitive profile of the children concerned. Previous studies have reported deficits in visuospatial/nonverbal and planning tasks. This systematic review of the literature aims to determine if impairments can be found in other attentional and executive functions as well. The type of cognitive tasks, the tasks’ modality (verbal/nonverbal), and the influence of comorbid disorders on attentional and executive profiles are systematically considered. Forty-one studies were identified through the PubMed/Medline and PsycINFO databases according to pre-established eligibility criteria. The results reveal weaknesses in inhibitory control, working memory, planning, nonverbal fluency, and general executive functioning in children with DCD. The presence of comorbid disorders seemingly contributes to the verbal working memory difficulties findings. This review contributes to a better understanding of the cognitive impairments in DCD and of the needs of children with this disorder, allowing to optimize practitioners’ therapeutic interventions.

Distress-driven impulsivity interacts with cognitive inflexibility to determine addiction-like eating

BACKGROUND

Researchers are only just beginning to understand the neurocognitive drivers of addiction-like eating behaviours, a highly distressing and relatively common condition. Two constructs have been consistently linked to addiction-like eating: distress-driven impulsivity and cognitive inflexibility. Despite a large body of addiction research showing that impulsivity-related traits can interact with other risk markers to result in an especially heightened risk for addictive behaviours, no study to date has examined how distress-driven impulsivity interacts with cognitive inflexibility in relation to addiction-like eating behaviours. The current study examines the interactive contribution of distress-driven impulsivity and cognitive inflexibility to addiction-like eating behaviours.

METHOD

One hundred and thirty-one participants [mean age 21 years (SD = 2.3), 61.8% female] completed the modified Yale Food Addiction Scale, the S-UPPS-P impulsivity scale, and a cognitive flexibility task. A bootstrap method was used to examine the associations between distress-driven impulsivity, cognitive inflexibility, and their interaction with addiction-like eating behaviours.

RESULTS

There was a significant interaction effect between distress-driven impulsivity and cognitive flexibility (P = 0.03). The follow-up test revealed that higher distress-driven impulsivity was associated with more addiction-like eating behaviours among participants classified as cognitively inflexible only.

CONCLUSION

The current findings shed light on the mechanisms underlying addiction-like eating behaviours, including how traits and cognition might interact to drive them. The findings also suggest that interventions that directly address distress-driven impulsivity and cognitive inflexibility might be effective in reducing risk for addiction-like eating and related disorders.

Clinical and Cognitive Functioning Changes After Partial Hospitalization in Patients With Anorexia Nervosa

Introduction: Anorexia nervosa is usually associated with emotional and cognitive difficulties. Little knowledge is available about the changes in cognitive functioning in patients undergoing treatments. The aim of the present study was to longitudinally assess the impact of partial hospitalization on clinical and cognitive functioning in anorexia nervosa. Materials and Methods: 56 women with anorexia nervosa according to DSM-5 criteria and 58 healthy women were enrolled in the study. At baseline, all participants underwent clinical, diagnostic and neuropsychological assessment (T0). Patients were also assessed at the end of the treatment program (T1; n = 56). Results: BMI improved significantly throughout treatment. At baseline, patients showed significantly poorer executive abilities and less specific autobiographical memory. After the day-hospital program, decision-making abilities improved significantly. Response to treatment was predicted by BMI at admission and duration of illness, but neuropsychological performance did not contribute to the prediction model. Discussion: Cognitive difficulties, mostly regarding executive functions, resulted differently affected by clinical improvement. In particular, while cognitive monitoring and cognitive inhibition appear to be mostly stable trait-like characteristics, decision-making is both more state-dependent and sensitive to clinical status. None of the cognitive variables added information about the response to day hospital treatment; patients with short duration of illness and a rapidly decreasing BMI would benefit more from intensive interventions than less "acute" patients. These observations, if confirmed by future studies, have important clinical implications in order to understand the impact of malnutrition on cognitive functioning and to provide individualized effective treatment for patients with anorexia nervosa.

Food-related impulsivity assessed by longitudinal laboratory tasks is reduced in patients with binge eating disorder in a randomized controlled trial

Food-related impulsivity, i.e. a food-related attentional bias proposed to be due to increased reward sensitivity and diminished inhibitory control, has been cross-sectionally associated with binge eating disorder. To analyze changes in food-related impulsivity, we implemented longitudinal analyses of objective laboratory tasks in a randomized controlled trial called IMPULS. Patients who attended an impulsivity-focused group intervention (IG N = 31) and control patients who did not take part in the intervention (CG N = 25) were compared before (T0) and after the intervention period (T1) and at three months follow-up (T2). Patients’ impulsive gaze behavior towards food vs. neutral stimuli was measured in two eye tracking paradigms, one addressing reward sensitivity and another addressing inhibitory control. Initial fixations of food vs. neutral stimuli were increased at T0 (IG: p = .014, CG: p = .001), but not at T1 and T2 in IG (T1: p = .178, T2: p = .203) and in CG after Bonferroni correction only at T2 (T1: p = .031, T2: p = .002). Patients from IG increased dwell time on neutral stimuli at T1 contrary to patients from CG (p = .016) and rated the presented food stimuli as less positive (e.g. pleasantness p < .001 at T1 and T2). A possible explanation for this observation is reduced reward sensitivity, which implies a short-term treatment effect. Both groups showed improvement in inhibiting eye movements towards food and neutral stimuli over time (i.e. first saccade errors overall p < .001, second saccade errors overall p < .003). This could indicate increased inhibitory control due to training effects from the study paradigm. The results suggest that food-related impulsivity represents an underlying mechanism of BED and that it is modifiable by cognitive behavioral interventions.

Increased cognitive flexibility mediates the improvement of eating disorders symptoms, depressive symptoms and level of daily life functioning in patients with anorexia nervosa treated in specialised centres

OBJECTIVE

Poor cognitive flexibility has been highlighted in patients with anorexia nervosa (AN), contributing to the development and maintenance of symptoms. The aim of the present study is to investigate how enhanced cognitive flexibility is involved in treatment outcomes in patients with AN.

METHOD

One hundred thirty female out-patients treated for AN have been assessed at baseline and after 4 months of treatment. Path analyses were used to investigate the mediating role of cognitive flexibility, measured through the Brixton test, on a wide range of outcomes: body mass index, eating disorder symptoms, daily life functioning, anxiety, depression, emotions, self-rated silhouette.

RESULTS

Cognitive flexibility was improved during treatment, and enhanced cognitive flexibility explains a significant part of level of the improvement in daily life functioning (26%), reduction of eating disorder symptoms (18%) and reduction of depressive symptoms (17%). Others outcomes were also improved, but these improvements were not mediated by cognitive flexibility.

CONCLUSIONS

Results suggest that enhancing cognitive flexibility could help reduce rigid cognitive and behavioural patterns involved in AN, thus improving everyday functioning and clinical severity. Further studies combining different types of cognitive flexibility evaluation as well as neuroimaging may be necessary to better establish which of its aspects are involved in patients' improvement.

Are poor set-shifting and central coherence associated with everyday function in anorexia nervosa? A systematic review

BACKGROUND

There is increasing interest in associations between cognitive impairments and clinical symptoms in Anorexia Nervosa (AN), however, the relationship with everyday function is unclear. The current review synthesizes existing data regarding associations between scores on tests of set-shifting and central coherence and functional outcome measures for individuals with AN.

METHOD

A systematic electronic database search yielded 13 studies which included participants with current or lifetime AN where scores on a neuropsychological test of set-shifting or central coherence were directly or indirectly compared to a functional outcome measure.

RESULTS

Associations between set-shifting and central coherence performance measures and functional outcomes were limited in number and noted only in adult or mixed-age cohorts. Associations were noted at subscale level, suggesting they are specific in nature. In younger cohorts, assessments of executive functioning in everyday life appear sensitive to cognitive-behavioral flexibility issues.

CONCLUSIONS

Associations between cognitive performance and functional outcome have not been as systematically assessed in AN as in other psychiatric disorders. Key factors to address in future research include: (a) the use of function measures which are sensitive to both the level of impairment, and specific rather than general impairments (b) the ecological validity of measures, (c) the task impurity problem, especially in regard to cognitive flexibility assessment, and (d) the need to measure both cognitive deficits and strengths, because tests of specific cognitive processes may underestimate the ability to function in daily life due to compensatory strategies.

Considerations for using the Wisconsin Card Sorting Test to assess cognitive flexibility

The Wisconsin Card Sorting Test (WCST) is a popular neurocognitive task used to assess cognitive flexibility, and aspects of executive functioning more broadly, in research and clinical practice. Despite its widespread use and the development of an updated WCST manual in 1993, confusion remains in the literature about how to score the WCST, and importantly, how to interpret the outcome variables as indicators of cognitive flexibility. This critical review provides an overview of the changes in the WCST, how existing scoring methods of the task differ, the key terminology and how these relate to the assessment of cognitive flexibility, and issues with the use of the WCST across the literature. In particular, this review focuses on the confusion between the terms 'perseverative responses' and 'perseverative errors' and the inconsistent scoring of these variables. To our knowledge, this critical review is the first of its kind to focus on the inherent issues surrounding the WCST when used as an assessment of cognitive flexibility. We provide recommendations to overcome these and other issues when using the WCST in future research and clinical practice.

Central coherence and set-shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis compared previously documented inefficiencies in central coherence and set-shifting between people with nonunderweight eating disorders (bulimia nervosa and binge-eating disorder) and people with anorexia nervosa.

METHOD

We performed random-effects meta-analyses on 16 studies (1,112 participants) for central coherence and 38 studies (3,505 participants) for set-shifting. Random effects meta-regressions were used to test whether the effect sizes for people with nonunderweight eating disorders were significantly different from the effect sizes for people with anorexia nervosa.

RESULTS

People with anorexia nervosa (Hedge's g = -0.53, 95% CIs: -0.80, -0.27, p < .001) and bulimia nervosa (Hedge's g = -0.70, 95% CIs: -1.14, -0.25, p = .002), but not binge-eating disorder, had significantly poorer central coherence than healthy controls. Similarly, people with anorexia nervosa (Hedge's g = -0.38, 95% CIs: -0.50, -0.26, p < .001) and bulimia nervosa (Hedge's g = -0.55, 95% CIs: -0.81, -0.29, p < .001), but not binge-eating disorder, had significantly poorer set-shifting than healthy controls. The effect sizes for people with nonunderweight eating disorders did not significantly differ from those for people with anorexia nervosa.

DISCUSSION

Our meta-analysis was underpowered to make definitive judgments about people with binge-eating disorder. However, we found that people with bulimia nervosa clearly have central coherence and set-shifting inefficiencies which do not significantly differ from those observed in people with anorexia nervosa. Clinically, this suggests that people with bulimia nervosa might benefit from adjunctive approaches to address these inefficiencies, such as cognitive remediation therapy.