Cognitive performance in patients with bulimia nervosa: relationship to intermittent starvation

The complexity of the interaction between binge-eating and attention

OBJECTIVE

To investigate whether binge-eating in patients with eating disorders (EDs) is associated with attentional deficits.

METHODS

We studied ED patients with binge-eating (n = 51), no binge-eating (n = 59) and controls (n = 58). ED patients were assessed following the stabilization of weight and ED pathology. Attention assessment included evaluation of attention deficit hyperactivity disorder (ADHD) diagnosis, the Adult ADHD Self-Report (ASRS) and ADHD Rating Scale-IV-Home Version (ADHD-RS) questionnaires, and attention functioning assessed with neuropsychological tools. The severity of eating-related pathology, depression, anxiety and obsessionality was also monitored.

RESULTS

Patients with binge-eating showed more ADHD symptomatology on the ADHD-RS compared with non-binge-eating patients. No differences were found between binge-eating and non-binge-eating patients in ADHD diagnosis and neuropsychological functioning. Among the specific ED subtypes, patients with anorexia nervosa binge/purge type (AN-B/P) showed the highest rates of ADHD symptomatology on the ADHD-RS, and were characterized with sustained attention deficits.

CONCLUSION

Binge-eating is not associated with attention deficits as measured by objective neuropsychological tools. Nonetheless, it is associated with attentional difficulties as measured with the self-reported ADHD-RS. AN-B/P patients are the only ED category showing objective sustained attention deficits.

Relation of Dieting in College and High School Students to Symptoms Associated with Semi-starvation

Dieting and concern with weight were found to be associated with psychological and neurological symptoms observed in cases of severe semi-starvation. College students of both sexes ( n 292) and high school females ( n121) rated themselves on dietary restraint and psychological and physical symptoms that were prevalent in men after 24 weeks in the Minnesota semi-starvation experiment of 1944–5. Apprehension, irritability, and moodiness were associated with a high concern with restraint. Blank spells, hunger pain, concern for health, and social withdrawal were associated with a history of restraint. Depression, lower self-esteem, eating behavior patterns, apathy, and decreased motivation were associated with both restraint parameters. Our results suggest that normal dieting may be more closely related to psychological and health risks associated with chronic semi-starvation than is commonly believed.

Neurocognition in bulimic eating disorders: a systematic review

Van den Eynde F, Guillaume S, Broadbent H, Stahl D, Campbell IC, Schmidt U, Tchanturia K. Neurocognition in bulimic eating disorders: a systematic review.

OBJECTIVE

  The aim of this study was to review the literature on neurocognition comparing people with a bulimic eating disorder in the acute phase of the illness with healthy controls (HC).

METHOD

  The review follows the PRISMA (preferred reporting items for systematic reviews and meta-analysis) statement guidelines. Three databases (Medline, Web of Science, and Scopus) were searched combining the search terms 'bulimic disorder', 'bulimia nervosa (BN)', 'binge-eating disorder (BED)' with terms referring to cognitive domains (e.g. 'executive functions').

RESULTS

  Thirty-seven studies on people with BN and four on people with BED were selected for review. Overall, sample sizes were relatively small [bulimic disorders: median and range 22 (12-83); HC: 27 (13-172)]. The diversity in methodology precluded a meta-analytical approach. People with a bulimic disorder did not present with a clear neurocognitive profile. Inclusion of salient, disorder-related stimuli (e.g. body weight/shape words) in the neurocognitive paradigms tended to generate differences between people with a bulimic disorder and HC.

CONCLUSION

  Neurocognition in bulimic eating disorders is under researched, and the available evidence is inconclusive. This review outlines strategies for further research in this area.

Quantitative evidence for distinct cognitive impairment in anorexia nervosa and bulimia nervosa

It is generally agreed that at least some aspects of abnormal eating behaviour is indeed due in part to disordered cognition. The accumulated literature illustrates cognitive impairment in patients with anorexia nervosa (AN) and bulimia nervosa (BN). Yet beyond being inconsistent, these independent studies also do not reveal the magnitude of impairment within and across studies and fail to give due consideration to the magnitude of impairment so as to understand the severity and breadth of impairment and/or differences in cognitive profiles between patients with AN and BN. Hence, the present review on the subject sought to articulate the magnitude of cognitive impairment in patients with AN and BN by quantitatively synthesizing the existing literature using meta-analytic methodology. The results demonstrate modest evidence of cognitive impairment specific to AN and BN that is related to body mass index in AN in terms of its severity, and is differentially impaired between disorders. Together, these results suggest that disturbed cognition is figural in the presentation of eating disorders and may serve to play an integral role in its cause and maintenance. Implications of these findings with respects to future research are discussed.

Neuropsychological function in bulimia with comorbid borderline personality disorder and depression

BACKGROUND

In bulimia nervosa (BN), borderline personality disorder (BPD) and major depression (MDD) are frequently comorbid conditions. Executive function has been found to be impaired in BPD and MDD, but the impact of comorbidity on neuropsychological function has rarely been investigated.

OBJECTIVE

To investigate neuropsychological function in BN with a focus on comorbid BPD and MDD.

METHODS

One hundred forty-four medication-free female patients entering a study of psychological treatments for BN performed a brief battery of neuropsychological tests. Comorbid MDD and BPD were systematically identified using standard interviews. Neuropsychological test results were compared.

RESULTS

Forty-one subjects had comorbid BPD and 35 had comorbid MDD, while 15 had both. There was no effect of comorbid MDD, but there was a significant effect of BPD and a significant interaction between the diagnosis of MDD and BPD on executive tasks (trail making and Stroop). Thus, compared with subjects without BPD, subjects with BPD performed significantly worse on tests of executive function, while the group with both comorbidities performed even worse.

CONCLUSIONS

There appears to be an additive effect of BPD and MDD resulting in impaired executive neuropsychological function. Future studies on either disorder and on BN should examine and account for the effect of comorbidity.

Urinary steroids in young women with eating disorders

Urinary steroid components were measured after enzyme hydrolysis and methoxym-silyl derivatization by capillary gas chromatography in young women with eating disorders. Using three internal standards, programmed temperature from 50 to 300 degrees C and flame ionization detection, on ULTRA-1 capillary column the separation of 28 steroid components is possible. Fifteen young women with different eating disorders, i.e. anorexia nervosa, bulimia nervosa and bulimarexia (aged 16-28 years) and 15 healthy women (aged 22-26 years) collected 24-h urine. A significant decrease of dehydroepiandrosterone (p<0.05) and a significant elevation of the stress marker allo-tetrahydrocorticosterone (p<0.05) were observed in the patients with compared to the controls. Among the patients two groups were defined due to a significant difference in the content of the cortisol metabolites compared to each other and to controls (p<0.01). The results confirm the role of dehydroepiandrosterone in eating disorders. The increased level of the stress marker allo-tetrahydrocorticosterone refers to the involvement of stress in these diseases, but the relevance of hormone alteration to the pathophysiology of eating disorders remains to be elucidated. The reason of the differences in cortisol metabolites levels in some patients needs further investigations.

Cognitive flexibility in anorexia nervosa and bulimia nervosa

The aim of this study was to determine if there are differences in cognitive flexibility in anorexia nervosa and bulimia nervosa. Fifty-three patients with an eating disorder (34 with anorexia nervosa and 19 with bulimia nervosa) and 35 healthy controls participated in the study. A battery of neuropsychological tests for cognitive flexibility was used, including Trail Making B, the Brixton Test, Verbal Fluency, the Haptic Illusion Test, a cognitive shifting task (CatBat) and a picture set test. Using exploratory factor analysis, four factors were obtained: 1: Simple Alternation; 2: Mental Flexibility; 3: Perseveration; and 4: Perceptual Shift. Patients with anorexia nervosa had abnormal scores on Factors 1 and 4. Patients with bulimia nervosa showed a different pattern, with significant impairments in Factors 2 and 4. These findings suggest that differential neuropsychological disturbance in the domain of mental flexibility/rigidity may underlie the spectrum of eating disorders.

Neuropsicologia dos transtornos alimentares: revisão sistemática da literatura

ANTECEDENTES: A etiologia dos transtornos alimentares (TA) ainda não se encontra estabelecida. Dentre os diversos fatores envolvidos, a hipótese de uma disfunção do sistema nervoso central tem sido explorada de diversas maneiras. Assim, a avaliação neuropsicológica de pacientes com TA tem por finalidade investigar a ocorrência de déficits cognitivos associados a estas patologias. OBJETIVOS: O objetivo deste artigo é avaliar o estado atual das investigações sobre a avaliação neuropsicológica em pacientes com TA. MÉTODOS: Foi realizada uma pesquisa bibliográfica - utilizando as seguintes bases de dados como estratégias de procura: MedLINE, PsychoINFO, LILACS e Cochrane Data Bank -, procurando artigos relacionados ao tema e publicados até o ano de 2004. RESULTADOS: A anorexia nervosa é o transtorno alimentar que conta com mais estudos neuropsicológicos e, de uma forma geral, os resultados apontam para déficits de atenção, déficits viso-espaciais e de viso-construção. Na bulimia nervosa, as alterações mais encontradas são déficits de atenção seletiva e das funções executivas. O transtorno da compulsão alimentar periódica ainda não conta com estudos neuropsicológicos até o momento. Após um tratamento bem-sucedido do transtorno alimentar, embora haja uma diminuição dos déficits cognitivos, algumas alterações cognitivas parecem persistir. CONCLUSÕES: Os transtornos alimentares parecem estar associados a algum grau de disfunção neuropsicológica, muito embora as funções específicas que se apresentam deficitárias variem entre os estudos encontrados, talvez em decorrência de variações metodológicas. O fato de que, após o tratamento, alguns pacientes apresentem uma melhora no funcionamento cognitivo poderia indicar que, em alguns casos, os déficits seriam funcionais. A ausência de melhora no funcionamento cognitivo de alguns pacientes, após diversas formas de intervenção, pode sugerir que estes déficits antecederiam o desenvolvimento dos transtornos alimentares, podendo, assim, contribuir para seu desenvolvimento ou para um pior prognóstico. O melhor delineamento do perfil cognitivo dos pacientes com transtorno alimentar torna-se importante para orientar abordagens terapêuticas mais seletivas.

The effect of self-initiated weight-loss dieting on working memory: the role of preoccupying cognitions

This study investigated the effects of weight loss dieting on the components of working memory and the extent to which these effects were mediated by preoccupying cognitions concerning food, diet and body shape. A dual task paradigm was used in which dieters (n=20) and non-dieters (n=20) completed mental arithmetic problems concurrently with suppression tasks designed to engage the central executive, phonological loop, and visuo-spatial sketchpad components of working memory. In addition, tasks reflecting the articulatory control process and phonological store sub-components of the phonological loop were also completed. Results showed that dieters performed more poorly on measures of the central executive and the phonological loop compared with non-dieters. Dieters reported higher levels of preoccupying cognitions which mediated the relationship between dieting status and functioning of the central executive and phonological loop, and the phonological store in particular.

Neurocognitive functioning in subjects with eating disorders: the influence of neuroactive steroids

BACKGROUND

Neuropsychological studies in subjects with eating disorders (EDs) have reported conflicting findings, which might be accounted for by several confounding variables, including neuroendocrine changes.

METHODS

General abilities, executive functions, attention, and noneffortful learning were assessed in 45 patients with EDs and 45 healthy comparison subjects (HCS). Plasma levels of 17beta-estradiol, cortisol, allopregnanolone, dehydroepiandrosterone and its sulfate metabolite (DHEA and DHEAS) were evaluated in a subsample of patients and HCS. The influence of clinical, demographic, and neuroendocrine variables on neurocognitive performance was explored.

RESULTS

Patients were slower than HCS on noneffortful learning and more accurate on a spatial executive task. DHEA and DHEAS were increased and positively correlated with accuracy on the executive task, while cortisol positively correlated with speed of noneffortful learning.

CONCLUSIONS

A subtle impairment of noneffortful learning is the only neuropsychological deficit in patients with EDs. Changes in neuroactive steroids influence neurocognitive performance.

Preoccupation, food, and failure: an investigation of cognitive performance deficits in dieters

OBJECTIVE

This study tested two explanations of the cognitive performance deficits of dieters. First, these deficits are due to the metabolic consequences of food deprivation. Second, they are psychological in origin (i.e., preoccupation with dieting-related thoughts during dieting depletes the cognitive resources available for nondieting tasks).

METHOD

Dieters and nondieters performed a battery of cognitive tasks before and after consumption of a high-energy chocolate bar. Eating the chocolate bar was expected to reverse the effects of food deprivation but, as a "diet-threatening" food, it could increase dieting-related preoccupation.

RESULTS AND CONCLUSIONS

The results supported the latter prediction. Performance on a memory task was further impaired, rather than improved, after food consumption in dieters. In addition, dieters experienced a significant increase in the number of food and dieting-related thoughts. Some dieters attributed their poorer performance to distraction by these thoughts. Marked individual differences in thought content accounted for some of the variability in the effects on performance.

The effect of weight-loss dieting on cognitive performance and psychological well-being in overweight women

This study investigated the effect of a weight reduction diet on cognitive performance and psychological well-being among overweight women. A total of 42 women undertook a 12-week weight reduction diet while 21 women maintained their usual diet and exercise habits for 12 weeks. All women completed neuropsychologcial tests of speed of information processing, executive function, working memory, immediate and delayed recall and recognition, and verbal ability. They also completed measures of weight locus of control, dieting beliefs, self-esteem, mood and dysfunctional attitudes, before and after the 12-week interval. Being on the diet had a minimal impact on cognitive performance and a positive effect on emotional eating, feelings of depression and dysfunctional attitudes. A sense of control over weight and eating behaviour increased among the dieters, but an internal locus of control was negatively related to self-esteem.

Eating habits and appetite control: a psychobiological perspective

An individual's eating behaviour is shaped by factors ranging from economic conditions and cultural practices to biological influences. The physiological system controlling appetite appears to be adapted to solving the problem of an unevenness of food supply across time, and is fairly permissive in its response to undereating and overeating. Consequently, when food is abundant, the diet is energy dense and energy expenditure is low, there is a strong tendency to become obese (i.e. obesity is better viewed as due to a 'toxic' environment than to faulty physiological control of appetite). Under such conditions the most common method of avoiding obesity is through the cognitive control of eating. However, dietary restraint and dieting are demanding tasks, and are associated with psychological costs, including significant impairment of cognitive performance. Restraint is also prone to disinhibition, with the result that it can sometimes undermine eating control, even leading to the development of highly disordered eating patterns. In part, these difficulties are due to the self-perpetuating nature of dietary habits: for example, hunger tends to be diminished during strict unbroken dieting, but increased in individuals having a highly variable eating pattern (such as occurs when eating is frequently disinhibited). These features of appetite control provide both barriers and opportunities for changing behaviour. Accordingly, there is a need for future research to focus on the psycho-social factors and the dieting practices predicting successful eating and weight control, with the objective of identifying the actual cognitive and behavioural strategies used by the many dieters and restrained eaters who are able to achieve weight loss and maintain long-term weight stability.

Cognitive functioning, weight change and therapy in anorexia nervosa

Anorexia nervosa is associated with impairments in cognitive function which have been hypothesized to be fundamentally attentional in nature. The current study investigated whether therapy and weight gain affect these impairments. A group of anorexics (N = 12) completed a battery of cognitive performance tasks and self-report measures of psychopathology on three occasions, over the course of 12 weeks of in-patient treatment. A non-clinical control population (N = 17) completed the same measures. The anorexics improved on all measures of psychopathology and affective state as a result of therapy. Anorexics displayed poorer recall, reaction times, and motor speed than the control subjects. Although there was a gain in weight over the course of therapy, there was no corresponding improvement in cognitive performance. Impaired task performance in anorexics was not directly related to their psychopathology or affective state.

The self-schema model: a theoretical approach to the self-concept in eating disorders

Over the last several decades, the self-concept has been implicated as a important determinant of eating disorders (ED). Although considerable progress has been made, questions remain unanswered about the properties of self-concept that distinguish women with an ED from other populations, and mechanisms that link the self-concept to the disordered behaviors. Markus's self-schema model is presented as a theoretical approach to explore the role of the self-concept in ED. To show how the schema model can be integrated with existing work on the self-concept in ED, a framework is proposed that addresses the number, content, and accessibility of the self-schemas. More specifically, it is posited that a limited collection of positive self-schemas available in memory, in combination with a chronically and inflexibly accessible body-weight self-schema, lead to the disordered behaviors associated with anorexia nervosa and bulimia nervosa.

Impaired cognitive functioning during spontaneous dieting

In one of a continuing series of studies, the cognitive performance of normal weight female dieters was compared on two sessions, 3 weeks apart. Those who reported themselves as being on a weight-reducing diet on only one of the two sessions displayed poorer vigilance performance, slower reaction times and poorer immediate recall of words when they were dieting. In contrast, performance on a low processing load tapping task was unaffected. Self-report measures showed that dietary restraint, but not state anxiety or depression was increased during dieting. These results are interpreted in terms of an association between dieting behaviour and high levels of distractibility, and extend earlier findings by demonstrating that these deficits in cognitive performance are closely related to dieting or the perceived need to diet per se.

Lack of effect of short-term fasting on cognitive function

In a study designed to assess the effects of short-term food deprivation on cognitive function, a sample of female subjects (N = 21) was tested on a number of measures of cognitive function after three levels of food deprivation (miss one meal, miss two meals or miss all food for 24 h prior to testing) and a condition in which they ate normally for 24 h prior to testing. There was found to be no significant effects of food deprivation on sustained attention, attentional focus, simple reaction time or immediate memory. However, performance on a low processing load tapping task was significantly poorer when the subjects were deprived of food for 24 h prior to testing, and heart rate was significantly higher when they were non-deprived. These results stand in contrast to the impairments in cognitive function previously found to be associated with spontaneous dieting behaviour (using essentially the same task battery).

Impairment of cognitive performance associated with dieting and high levels of dietary restraint

Seventy women students were tested on a short battery of tasks assessing cognitive performance. They also completed self-report ratings of mood, the Dutch Eating Behaviour Questionnaire (DEBQ) to which was appended several additional items concerning their recent dieting behaviour, and a 24-h dietary recall. Heart rate was measured before and after testing. Compared with nondieting subjects with low to moderate scores on the restraint factor of the DEBQ, subjects (n = 15) who reported that they were currently dieting to lose weight displayed impaired performance on a vigilance task and also tended to show poorer immediate memory and longer reaction times. Highly restrained eaters who were not dieting at the time of testing, on the whole, performed at an intermediate level on these tests. In contrast, the dieters tended to show the best performance on an undemanding finger tapping task, indicating that they were not slowed in their fine motor responses or lacking in motivation to carry out the tasks. Poorer cognitive functioning during dieting could arise as a direct consequence of the effects of food restriction on energy metabolism or other physiological mechanisms--the dietary records indicated that the current dieters were eating at about 70% of maintenance energy requirement. However, it is also possible that cognitive performance is impaired during dieting due to anxiety resulting from stressful effects of imposing and maintaining dietary restraint.