Control over interfering memories in eating disorders

Overlap of eating disorders and neurodivergence: the role of inhibitory control

BACKGROUND

Difficulties with inhibitory control have been identified in eating disorders (EDs) and neurodevelopmental disorders (NDs; including attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder), and there appear to be parallels between the expression of these impairments. It is theorised that impairments in inhibitory control within NDs may represent a unique vulnerability for eating disorders (EDs), and this same mechanism may contribute to poorer treatment outcomes. This review seeks to determine the state of the literature concerning the role of inhibitory control in the overlap of EDs and neurodivergence.

METHOD

A scoping review was conducted to summarise extant research, and to identify gaps in the existing knowledge base. Scopus, Medline, PsycInfo, Embase, and ProQuest were systematically searched. Studies were included if the study measured traits of ADHD or autism, and symptoms of ED, and required participants to complete a performance task measure of inhibitory control. Where studies included a cohort with both an ND and ED, these results had to be reported separately from cohorts with a singular diagnosis. Studies were required to be published in English, within the last 10 years.

RESULTS

No studies explored the relationship between autism and EDs using behavioural measures of inhibitory control. Four studies exploring the relationship between ADHD and EDs using behavioural measures of inhibitory control met selection criteria. These studies showed a multifaceted relationship between these conditions, with differences emerging between domains of inhibitory control. ADHD symptoms predicted poorer performance on measures of response inhibition in a non-clinical sample; this was not replicated in clinical samples, nor was there a significant association with EDs. Both ADHD and ED symptoms are associated with poor performance on attentional control measures; where these diagnoses were combined, performance was worse than for those with a singular diagnosis of ADHD. This was not replicated when compared to those with only ED diagnoses.

CONCLUSION

Impairments in attentional control may represent a unique vulnerability for the development of an ED and contribute to poor treatment outcomes. Further research is needed to explore the role of inhibitory control in EDs, ADHD and autism, including the use of both self-report and behavioural measures to capture the domains of inhibitory control.

The validity and reliability of the Test of Memory Strategies among Italian healthy adults

Background

Previous literature has shown that executive functions (EF) are related to performance in memory (M) tasks. Nevertheless, there is a shortage of psychometric tests that examine these two constructs simultaneously. The Test of Memory Strategies (TMS; previously validated in Spain and Portugal) could be a useful verbal learning task that evaluates these two constructs at once. In this study, we aimed to evaluate the psychometric properties of the TMS in an Italian adult sample.

Method

One hundred twenty-one healthy volunteers (74 F, Mean age = 45.9 years old, SD = 20.4) who underwent a neuropsychological examination participated in this study. We conducted a Confirmatory factor analysis (CFA) to evaluate the structural validity of the TMS. We conducted a latent variable analysis to examine convergent and discriminant validity of the TMS sub-scale scores reflecting executive functions and memory. We also examined the TMS reliability in terms of internal consistency through the McDonald's omega.

Results

The CFA confirmed the expectation that the TMS-1 and TMS-2 subtests reflect a factor and that the TMS-3, TMS-4, and TMS-5 subtests reflect a different factor. This result is in line with the prediction that TMS-1 and TMS-2 require the use of executive functions and memory simultaneously, and therefore we called this factor executive functions (EF); whereas the TMS-3, TMS-4, and TMS-5 subtests require less involvement of executive functions, thus reflecting a construct that we named memory (M). The TMS subtests for EF and M showed convergent validity with the test scores using a traditional neuropsychological battery, assessing memory and executive functions separately. Finally, the reliability of the subtests was good.

Conclusions

These preliminary findings suggest that TMS is a valid and reliable scale to simultaneously assess M and EF while among Italian healthy adults.

Evaluation of cognitive impairment in a French sample of patients with restrictive anorexia nervosa: two distinct profiles emerged with differences in impaired functions and psychopathological symptoms

PURPOSE

The cognitive profiles of patients suffering from anorexia nervosa (AN) are currently explored as potential facilitating and/or maintenance factors. Specific data in restrictive AN (AN-R) remain contradictory. This study focused on women with AN-R to evaluate their cognitive functions to develop a more specific cognitive remediation program.

METHODS

Female patients older than 15 years who were suffering from AN-R were recruited in a specialized unit for eating disorder management. Female healthy control (HC) participants were recruited who were matched with AN patients on age. All participants completed a cognitive evaluation (premorbid intelligence quotient (IQ), planning, information processing speed, cognitive flexibility) and a clinical evaluation (impulsivity, anxiety, depression).

RESULTS

A total of 122 participants were included. Patients suffering from AN-R had significant impairment in information processing speed and planning. Patients exhibited significantly better cognitive flexibility than did the HC group when adjustments were made for other cognitive functions and impulsivity. Two distinct subgroups of patients were identified. The first subgroup had more marked cognitive impairment and fewer psychopathological symptoms than did the second subgroup of patients and the HC group.

CONCLUSION

Our results highlight cognitive impairment in patients with AN who had normal premorbid IQ. Two distinct profiles emerge. In clinical practice, these results open up perspectives for the development of more specific cognitive remediation programs (one specific program for cold cognitions and another specific program targeting emotions and hot cognitions). These results warrant confirmation by larger studies with a more specific evaluation of the impact of emotional status. Trial registration NTC02381639, Date of registration. March 6, 2015.

Testing the transdiagnostic hypothesis of inhibitory control deficits in addictions: An experimental study on gambling disorder

BACKGROUND AND AIMS

Many psychopathologies, including addictions, are characterized by inhibitory control deficits. In this regard, recent studies on substance-related disorders (SRD) have shown an impairment in the ability to inhibit potentially interfering memories, despite preserved motor inhibition. To investigate whether the same dissociation could also characterize gambling disorder (GD) in a transdiagnostic perspective, we tested both cognitive and motor inhibitory processes through dedicated tasks, for the first time in this behavioral addiction.

METHODS

30 outpatients with GD and 30 healthy controls performed a go/no-go task addressing the integrity of motor inhibition, and the Retrieval Practice Paradigm, a task addressing the integrity of memory inhibition as indexed by the Retrieval-Induced Forgetting (RIF) effect. Self-report questionnaires assessing impulsivity were also administered.

RESULTS

Whereas RIF was similar across the two groups, patients showed more commission errors in the go/no-go task, and higher self-rated scores of impulsivity than controls.

DISCUSSION

The present findings suggest preserved memory inhibition and impaired motor response inhibition in GD, a pattern of inhibitory deficits opposite to that previously reported for SRD. Therefore, although both GD and SRD are characterized by altered inhibitory processing, a more fine-grained analysis revealed a specific inhibitory profile indicating vulnerability in different inhibitory components.

CONCLUSION

The present study highlights the need to investigate the multifaceted construct of inhibition more thoroughly, using performance measures able to assess its various components. This approach would enable to both better characterize different psychopathologies and orient their treatment.