Michael Kohn

Misinterpreting Emotional Expressions in Attention-Deficit/Hyperactivity Disorder: Evidence for a Neural Marker and Stimulant Effects

BACKGROUND In addition to cognitive impairment, there are disruptions to mood and emotion processing in attention-deficit/hyperactivity disorder (ADHD) but little is known about their neural basis. We examined ADHD disturbances in mood and emotion recognition and underlying neural systems before and after treatment with stimulant medication. METHODS Participants were 51 unmedicated ADHD adolescents and 51 matched healthy control subjects rated for depressed and anxious mood and accuracy for identifying facial expressions of basic emotion. Brain function was recorded using event-related potentials (ERPs) while subjects viewed these expressions. ADHD subjects were retested after 4 weeks, following treatment with methylphenidate (MPH). RESULTS ADHD subjects showed a profile of emotion-related impairment: higher depression and anxiety, deficits in identifying threat-related emotional expressions in particular, and alterations in ERPs. There was a pronounced reduction in occipital activity during the early perceptual analysis of emotional expression (within 120 msec), followed by an exaggeration of activity associated with structural encoding (120-220 msec) and subsequent reduction and slowing of temporal brain activity subserving context processing (300-400 msec). Methylphenidate normalized neural activity and produced some improvement of emotion recognition but had no impact on negative mood. Improvements in neural activity with MPH were consistent predictors of improvement in clinical features of emotional lability and hyperactivity. CONCLUSIONS Objective behavioral and brain function measures of emotion processing may provide a valuable addition to the clinical armamentarium for assessing emotional disturbances in ADHD and the efficacy of stimulants for treating these disturbances.

Development of an instrument to assess readiness to recover in anorexia nervosa.

OBJECTIVE The degree to which patients with anorexia nervosa demonstrate readiness to recover from their illness has received scant theoretical or empirical attention. Investigating the prevalence and degree of amotivation for recovery in anorexia nervosa, its role in outcome, and the effectiveness of interventions designed to enhance readiness to recover necessitates the existence of a reliable and valid measure of motivational issues relevant to the disorder. The present study aimed to develop and evaluate an instrument for assessing readiness to recover in anorexia nervosa, namely, the Anorexia Nervosa Stages of Change Questionnaire (ANSOCQ), a 23-item self-report questionnaire based on Prochaska and DiClementes stages of change model. METHOD Seventy-one inpatients with anorexia nervosa participated in the study. On several occasions during their admission, participants completed the ANSOCQ as well as questionnaires assessing readiness to recover, anorexic symptomatology, general distress, and social desirability. RESULTS The ANSOCQ demonstrated good internal consistency (.90) and 1-week test-retest reliability (.89). Various aspects of validity were also supported, such as significant relationships with other instruments assessing readiness to recover and the prediction of weight gain during different periods of treatment. DISCUSSION The results suggest that the ANSOCQ is a psychometrically sound instrument that may prove useful in investigating the role of readiness to recover in anorexia nervosa.

Exposure to early life trauma is associated with adult obesity

Exposure to traumatic events during childhood is associated with an elevated risk of adult obesity. It has been hypothesized that the psychological sequelae from childhood trauma account for this risk, though no study has examined whether an increased risk of obesity is found in persons without psychological disorders. We examined exposure to early life stressors and body mass index (BMI) in 696 adults without significant medical or psychiatric history. Bivariate correlation showed that the total number of early life stressors (r=0.08), age (r=0.19), and sex (r=0.16) were significantly related to adult BMI. Given the relationship between sex and BMI, we examined the contribution of early life stressors to adult obesity separately for men and women. In men, hierarchical regression showed that exposure to early life stressors predicted adult obesity. Specifically, history of being bullied/rejected (Obese 31%, Normal weight, 9%) and emotional abuse (Obese, 17%; Normal weight, 2%) predicted adult obesity after controlling for the effects of age. In women, no relationship between early life stressors and adult obesity was found. These findings suggest that multiple processes mediate the relationship between early life stress and adult obesity and that their relative contributions may differ between men and women.

Reversibility of cerebral ventricular enlargement in anorexia nervosa, demonstrated by quantitative magnetic resonance imaging☆☆☆★

OBJECTIVE To determine the reversibility of the loss of brain parenchyma and ventricular enlargement in patients with anorexia nervosa after refeeding. STUDY DESIGN Quantitative magnetic resonance imaging was performed on three groups of subjects: (1) 12 female adolescents hospitalized with anorexia nervosa, (2) the same 12 patients after nutritional rehabilitation, a mean of 11.1 months later, and (3) 12 healthy age-matched control subjects. Sixty-four contiguous coronal magnetic resonance images, 3.1 mm thick, were obtained. With a computerized morphometry system, lateral and third ventricular volumes were measured by a single observer unaware of the status of the patient. RESULTS On admission, patients were malnourished and had lost an average of 11.7 kg (body mass index, 14.3 +/- 2.0 kg/m2). After refeeding, they gained an average of 9.7 kg (body mass index, 17.9 +/- 1.5 kg/m2). Total ventricular volume decreased from 17.1 +/- 5.5 cm3 on admission to 12.4 +/- 3.0 cm3 after refeeding (p < 0.01) and returned to the normal range. The degree of enlargement of the third ventricle was greater than that of the lateral ventricles. There was a significant inverse relationship between body mass index and total ventricular volume (r = -0.63; p < 0.05). CONCLUSION In patients with anorexia nervosa, cerebral ventricular enlargement correlates with the degree of malnutrition and is reversible with weight gain during long-term follow-up.

DYNAMICS AND SPATIAL BEHAVIOR OF LIGHT EVOKED POTENTIALS, THEIR MODIFICATION UNDER HYPNOSIS, AND ON-LINE CORRELATION IN RELATION TO RHYTHMIC COMPONENTS.

The significance of evoked potentials recorded from scalp electrodes in response to stimuli might be made clearer if the relation of the shape and amplitude to the dynamics of the stimulus were known. The question may be asked to what extent evoked potentials represent a dynamic analog of the stimulus information, and how the nature of such analog would vary with the location from which they were recorded. Within the larger question of the coding of the information received by the brain one would like to know the relative parts played by all-or-none coded information patterns and codes using forms of analog representation. The object of the present study is to investigate the code displayed by the evoked potential, particularly with respect to the dynamic analog behaviour and its essential nonlinear coding with respect to rates of change of increasing and decreasing stimulus intensity. The present studies are confined to the spatial and temporal coding of the dynamics of stimulus intensity. In view of the number of clinical and research studies using evoked potentials, it is particularly desirable to obtain a clear understanding of the quantative dynamic nature of these potentials. Such a study can be undertaken irrespective of a definite theory of how these potentials arise from the behaviour of cells and nerve nets. In previous studies we have found unidirectional rate sensitivity to be a dynamic property of single channel biologic information systems. A corollary of these findings was the necessity for a biologic system to have two channels if information about rate of change in both directions was required to be tran~mitted.~.~ It appears from the present study that characteristic and different evoked potentials are elicited by increasing and decreasing rates of light intensity respectively which travel along noncongruent paths in the brain and that these two types of potentials are combined in the more complex forms of stimulation. It seems probable that the existence of these two types of potentials are related to the existence of the various on and of receptors in the retina.% * The work involved for this section of the paper was supported in part by Grant H-4170(C1) from the National Heart Institute and Grant B-2470(Cl) from the National Institute of Neurological Diseases and Blindness, Public Health Service, Bethesda, Md., and Grant G 14327 from the National Science Foundation,

Body mass index and neuropsychological function in healthy children and adolescents

Elevated body mass index (BMI) is associated with adverse neurocognitive outcome in adults, including reduced neuropsychological test performance. It is unknown whether this relationship also exists in children and adolescents. A total of 478 children and adolescents (age 6-19) without significant medical or psychiatric history provided demographic information and completed a computerized cognitive test battery. Participants were categorized using clinical criteria into underweight, normal weight, at risk for overweight and overweight groups based on age and gender. Partial correlation and MANCOVA analyses adjusting for age and intellectual function found no relationship between BMI and cognitive test performance in the full sample. However, analyses performed separately by gender showed that underweight females exhibited poorer memory performance than other female BMI groups. These findings suggest that elevated BMI is not associated with cognitive function in healthy children and adolescents, though underweight might be a risk factor for reduced memory performance in females. Further work is needed to clarify the inconsistent findings between adults and minors.

In first presentation adolescent anorexia nervosa, do cognitive markers of underweight status change with weight gain following a refeeding intervention?

OBJECTIVE To determine the nature and severity of cognitive functioning impairment in adolescent anorexia nervosa (AN) when underweight and following weight gain. METHOD In 37 first admission adolescent (12-18 years) AN patients and 45 matched controls, general cognitive functions were assessed at baseline and follow-up using the IntegNeuro-computerized battery. AN participants were tested between days 3 and 10 of their admission when underweight, with retesting conducted after weight restoration. RESULTS When underweight, AN participants performed more poorly than controls on sensori-motor speed tasks and exhibited a susceptibility to interference, but had superior working memory. Once the weight is restored, individuals significantly improved relative to their own performance. Relative to controls, they were significantly faster on attention and executive function tasks, exhibited superior verbal fluency, working memory, and a significantly superior ability to inhibit well-learnt responses. DISCUSSION Cognitive impairments in adolescent AN appear to normalize with refeeding and weight gain.

Sex differences in adolescent ADHD: findings from concurrent EEG and EDA

OBJECTIVE Attention Deficit Hyperactivity Disorder (ADHD) occurs more frequently in male children and adolescents than in females, with a ratio of approximately 3 to 1. We determined whether psychophysiological differences are associated with the expression of ADHD in males and females, using simultaneously recorded electroencephalography (EEG) and electrodermal activity (EDA). METHODS Quantitative EEG and EDA measures were acquired simultaneously and continuously (2min) during an eyes closed resting condition for 70 ADHD adolescents (48 males, 22 females) and their age- and sex-matched controls. RESULTS Males and females with ADHD were differentiated by both EEG theta activity and EDA. ADHD males showed increased theta (widespread), whereas ADHD females showed a localised frontal enhancement of theta with reduced rate of EDA decrement. These sex differences were unrelated to ADHD subtype. CONCLUSIONS These findings suggest that different psychophysiological processes may underlie ADHD in each sex. The profile of theta enhancement in ADHD males is consistent with a developmental deviation model of ADHD, whereas ADHD in females may be better understood within an arousal model, which emphasizes both central and autonomic function. SIGNIFICANCE These findings highlight the potential for concurrent EDA measures to inform EEG studies of ADHD, particularly in regard to sex differences.

Refeeding in anorexia nervosa: increased safety and efficiency through understanding the pathophysiology of protein calorie malnutrition

Purpose of review This paper reviews recent publications about the physiology associated with adaptation to malnutrition and refeeding (including the refeeding syndrome) and clinical outcomes of refeeding paradigms. Recent findings A number of recent reviews and original publications have highlighted important differences from the assumptions underpinning the current refeeding guidelines for patients with anorexia nervosa. The notion of ‘starting low and going slow’ with the prescription of daily calories seems unlikely to be important in preventing refeeding syndrome. Recent publications suggest this approach does not necessarily add to safety in the refeeding process but rather the contrary. It typically results in weight loss and protracts hospitalization and nutritional recovery. Rather, the composition of macronutrients, in particular avoiding a high proportion of calories from carbohydrates, appears to be more important than the absolute number of calories. The means of initial refeeding appears increasingly important in this process, particularly following descriptions of postprandial hypoglycemia. Summary The study supports a review of the current guidelines. Evidence for the use of continuous feeding strategies with less than 40% of calories from carbohydrates is presented. This approach has important implications for the prevention of the refeeding syndrome as well as the safety and efficiency with which refeeding may occur for children and adolescents with anorexia nervosa in hospital.

A randomized controlled trial of in-patient treatment for anorexia nervosa in medically unstable adolescents

Background Anorexia nervosa (AN) is a serious disorder incurring high costs due to hospitalization. International treatments vary, with prolonged hospitalizations in Europe and shorter hospitalizations in the USA. Uncontrolled studies suggest that longer initial hospitalizations that normalize weight produce better outcomes and fewer admissions than shorter hospitalizations with lower discharge weights. This study aimed to compare the effectiveness of hospitalization for weight restoration (WR) to medical stabilization (MS) in adolescent AN. Method We performed a randomized controlled trial (RCT) with 82 adolescents, aged 12–18 years, with a DSM-IV diagnosis of AN and medical instability, admitted to two pediatric units in Australia. Participants were randomized to shorter hospitalization for MS or longer hospitalization for WR to 90% expected body weight (EBW) for gender, age and height, both followed by 20 sessions of out-patient, manualized family-based treatment (FBT). Results The primary outcome was the number of hospital days, following initial admission, at the 12-month follow-up. Secondary outcomes were the total number of hospital days used up to 12 months and full remission, defined as healthy weight (>95% EBW) and a global Eating Disorder Examination (EDE) score within 1 standard deviation (s.d.) of published means. There was no significant difference between groups in hospital days following initial admission. There were significantly more total hospital days used and post-protocol FBT sessions in the WR group. There were no moderators of primary outcome but participants with higher eating psychopathology and compulsive features reported better clinical outcomes in the MS group. Conclusions Outcomes are similar with hospitalizations for MS or WR when combined with FBT. Cost savings would result from combining shorter hospitalization with FBT.