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

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.

Testing associations between assessments of cognitive flexibility and eating disorder symptoms in adolescent bulimia nervosa

OBJECTIVE

Cognitive rigidity, or difficulty adapting to changing demands, is commonly observed in anorexia nervosa. Less is known, however, about cognitive flexibility (CF) in bulimia nervosa (BN) and, particularly, adolescence. Clarifying this relation and best assessment practices may guide informed clinical decision-making. The current study compared how two measures of CF (i.e., Wisconsin Card Sort Task [WCST] and Trail Making Task [TMT]) relate to BN symptoms among adolescents.

METHODS

Data from a subsample (n = 78) of adolescents with BN were analyzed. Linear and hurdle regressions were used to compare the effects of WCST perseverative errors and TMT performance on Eating Disorder Examination Global Scores, objective binge episodes, and self-induced vomiting episodes (SVEs) at baseline and end-of-treatment (EOT).

RESULTS

Neither CF measure associated with baseline BN symptoms. TMT performance positively associated with the likelihood of engaging in SVEs at EOT (𝛽 = 0.47, p = 0.01, 95% confidence interval [CI] = [0.11-0.84]) and, among adolescents who endorsed ≥1 SVE at EOT, WCST perseverative errors (𝛽 = 0.05, p = 0.005, 95% CI = [0.01-0.08]) positively associated with SVE frequency at EOT.

DISCUSSION

The overall lack of associations between CF and outcomes suggests that cognitive rigidity may not be as relevant to the clinical profile of adolescent BN as for anorexia nervosa. In the few significant associations that emerged, the WCST and TMT uniquely predicted the severity of vomiting at EOT in this sample. Given the lack of CF deficits, future work should aim to test the role of other executive functions (e.g., impulsivity), in addition to CF, to determine which deficits are present in adolescent BN and may predict outcomes.

PUBLIC SIGNIFICANCE

Patients with eating disorders often have difficulties thinking flexibly, which may interfere with their recovery. We tested two ways of measuring flexible thinking in adolescents with BN. Overall, flexible thinking was not associated with symptom-level outcomes. However, less flexible thinking at the start of treatment predicted self-induced vomiting at EOT. If findings are replicable, then assessing and addressing flexible thinking could improve outcomes for adolescents with BN.

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.

Volume and complexity of the thalamus in Anorexia Nervosa: An exploratory evaluation

OBJECTIVE

Recent neuroscientific findings have highlighted the role of the thalamus in several cognitive functions, ranging from perception to cognitive flexibility, memory, and body representation. Since some of these functions may be involved in the pathophysiology of Anorexia Nervosa (AN), this study aims at exploring thalamic structure in different phases of the disorder.

METHOD

The sample included 38 patients with acute AN, 20 patients who fully recovered from AN (recAN), and 38 healthy controls (HC), all female. All participants underwent high-resolution MRI. The volumes of the whole thalamus and 25 thalamic nuclei were extracted using an automated segmentation algorithm, and thalamic fractal dimension was estimated using the calcFD toolbox.

RESULTS

Patients with acute AN, compared to HC, displayed reduced thalamic volume and complexity both at the whole level and at the level of specific nuclei. In patients recAN, instead, alterations were observed only at the level of the right laterodorsal and central lateral nuclei.

CONCLUSIONS

In the acute phase of the disorder patients with AN present a widespread reduction in thalamic volume and complexity. However, these alterations seem to normalise almost completely following weight restoration, thus suggesting the involvement of malnutrition-related mechanisms.

Food avoidance in anorexia nervosa: associated and predicting factors

PURPOSE

Qualitative food avoidance is a significant issue in patients with anorexia nervosa (AN) and restoring diet diversity is an important part of the treatment process. We aimed to identify clinical factors which drive food avoidance and predict its maintenance in patients with AN.

METHODS

In this multicentre longitudinal study, 130 female outpatients with AN were assessed before and after 4 months of care in clinical centres specialized in AN. We assessed levels of avoidance of 16 food items, as well as body mass index (BMI), eating disorder severity, symptoms of depression and anxiety, emotional state, daily-life functioning, and body image perception.

RESULTS

We found that qualitative food avoidance was associated with the clinical severity of AN, anxiety and mood dimensions, and BMI- and body image-related factors. A younger age at onset predicted the maintenance of food avoidance after 4 months of treatment. Additional exploratory analyses suggested that anxiety and negative affect caused food avoidance more than the opposite.

CONCLUSION

Qualitative food avoidance can be an indicator of illness severity. During treatment, focusing on reducing anxiety and negative affect may be a way to indirectly reduce food avoidance and restore diet diversity.

LEVEL OF EVIDENCE

Level III: Evidence obtained from cohort or case-control analytic studies.

Cognitive and clinical gender‐related differences among binge‐spectrum eating disorders: Analysis of therapy response predictors

OBJECTIVE

This study assessed gender-related differences in executive functions (decision-making, inhibitory control and cognitive flexibility), personality traits and psychopathological symptoms in binge-spectrum eating disorders (EDs). Secondly, we aimed to separately explore the predictive value of gender and executive functions in treatment outcome.

METHOD

A battery of self-reported and neurocognitive measures were answered by a sample of 85 patients (64 females) diagnosed with a binge-spectrum ED (41 BN; 44 binge eating disorder).

RESULTS

Data showed gender-related differences in executive functioning, displaying women lower inhibitory control and lower cognitive flexibility than men. Regarding personality traits and psychopathology symptoms, women presented higher reward dependence and cooperativeness, as well as more drive for thinness, body dissatisfaction, bulimia, and somatisation symptoms than men. Finally, worse executive functioning, particularly having lower ability in concept formation seems to predict worse treatment outcomes and dropout in these patients.

CONCLUSIONS

We described gender specific neuropsychological, personality and psychopathological impairments in patients with binge-spectrum EDs. Moreover, difficulties in executive functioning might have an impact on treatment response, since patients with a lower ability in concept formation are less likely to benefit from treatment. The present results can help improving current treatment approaches by tackling gender and individual differences.

Experiencing eight psychotherapy approaches devoted to eating disorders in a single-day workshop increases insight and motivation to engage in care: a pilot study

PURPOSE

For patients with eating disorders (EDs), early engagement in care is usually considered a positive prognostic factor. The aim of the study was to investigate how a single-day intervention devoted to early, brief, experiential exposure to a variety of psychotherapy approaches might support commitment to change and the decision to engage in care in patients with EDs.

METHODS

One hundred and sixty-nine adult outpatients newly diagnosed with an ED took part in a single-day workshop for groups of up to ten patients, where they experienced eight psychotherapeutic approaches. Motivation to change care and level of insight were assessed at baseline and 10 days after the intervention.

RESULTS

Motivation and commitment to take active steps toward change (expressed by the "Committed Action" composite score) significantly improved after the intervention (p < 0.001), and a significant number of patients specifically moved from "contemplation" to "action" stage (p < 0.001). The improvement of motivation to change was significantly associated with an increase in insight capacity (p < 0.001), and this increase was observed for almost all related dimensions such as recognition of illness or awareness of need for psychological treatment.

CONCLUSION

A single-day session devoted to experiencing a range of group psychotherapies increased patients' insight and motivation to actively engage in care. To confirm potential longer-term benefits of this intervention, further studies are needed to explore the contribution of each approach and process specifically involved in patients' increased motivation for care, as well as the clinical characteristics of patients associated with better outcomes.

LEVEL OF EVIDENCE

V: Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

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.

How Can Animal Models Inform the Understanding of Cognitive Inflexibility in Patients with Anorexia Nervosa?

Deficits in cognitive flexibility are consistently seen in patients with anorexia nervosa (AN). This type of cognitive impairment is thought to be associated with the persistence of AN because it leads to deeply ingrained patterns of thought and behaviour that are highly resistant to change. Neurobiological drivers of cognitive inflexibility have some commonalities with the abnormal brain functional outcomes described in patients with AN, including disrupted prefrontal cortical function, and dysregulated dopamine and serotonin neurotransmitter systems. The activity-based anorexia (ABA) model recapitulates the key features of AN in human patients, including rapid weight loss caused by self-starvation and hyperactivity, supporting its application in investigating the cognitive and neurobiological causes of pathological weight loss. The aim of this review is to describe the relationship between AN, neural function and cognitive flexibility in human patients, and to highlight how new techniques in behavioural neuroscience can improve the utility of animal models of AN to inform the development of novel therapeutics.

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.