Severe and Enduring Anorexia Nervosa: Enduring Wrong Assumptions?

To the extent that severe and lasting anorexia nervosa (SE-AN) is defined in terms of refractoriness to the best treatments available, it is mandatory to scrutinize the proven effectiveness of the treatments offered to patients. The array of so-called current evidence-based treatments for anorexia nervosa (AN) encompasses the entire spectrum of treatments ranging from specialized brand-type treatments to new treatments adapted to the specific characteristics of people suffering from AN. However, after several randomized control trials, parity in efficacy is the characteristic among these treatments. To further complicate the landscape of effective treatments, this "tie score" extends to the treatment originally conceived as control conditions, or treatment as usual conditions. In retrospection, one can understand that treatments considered to be the best treatments available in the past were unaware of their possible iatrogenic effects. Obviously, the same can be said of the theoretical assumptions underpinning such treatments. In either case, if the definition of chronicity mentioned above is applied, it is clear that the responsibility for the chronicity of the disorder says more about the flagrant inefficacy of the treatments and the defective assumptions underpinning them, than the nature of the disorder itself. A historical analysis traces the emergence of the current concept of "typical" AN and Hilde Bruch's contribution to it. It is concluded that today's diagnostic criteria resulting from a long process of acculturation distort rather than capture the essence of the disorder, as well as marginalizing and invalidating patients' perspectives.

Hyperactivity in anorexia nervosa: to warm or not to warm. That is the question (a translational research one).

In the Editorial 'Is the neglect of exercise in anorexia nervosa research a case of "running out" of ideas or do we need to take a "LEAP" of faith into the future?' these authors express their doubts concerning the suitability of keeping patients warm as a beneficial treatment option in managing excessive activity in anorexia nervosa (AN) patients. The case for warming as an adjunctive treatment for AN patients is based on strong experimental evidence gathered from research on animals with Activity-Based Anorexia (ABA). We posit that the beneficial effect of heat results, at least in part, from heat blocking the vicious cycle that hyperactivity plays on AN. Hyperactivity decreases caloric intake by interfering with feeding and increases energy expenditure through excess motor activity which in turn increases emaciation that further strengthens anorexic thinking.

Seasonal BMI differences between restrictive and purging anorexia nervosa subtypes.

OBJECTIVE: Seasonal differences in anorexia nervosa is an area of research which has received scarce attention in the literature. The aim of this study was to explore patterns of seasonal variation in body weight in anorexia nervosa patients admitted to an eating disorders unit from January 2007 to December 2011. METHOD: Anorexia nervosa restrictive (ANR) and binge eating/purging (ANBP) subtypes were compared with respect to BMI on admission during the Warm and Cold Semester, and in terms of lenght of hospital stay. RESULTS: The main result was that BMI differences between ANBP and ANR patients were due to bodyweight differences during the colder months of the year (p < 0.01) whereas no difference in bodyweight on admission was observed between both subtypes during the Warm Semester months. Furthermore, ANR patients' bodyweight was lower when admitted during the Cold compared to the Warm Semester (p < 0.05). Length of stay was significantly associated with reduced BMI in ANR patients (p < 0.01), but not so for ANBP patients. DISCUSSION: To our knowledge, this is the first study in the literature providing data on seasonal variations in the BMI on admission of anorexia nervosa patients, and in the length of hospitalization.

Rodent model of activity-based anorexia.

Activity-based anorexia (ABA) consists of a procedure that involves the simultaneous exposure of animals to a restricted feeding schedule, while free access is allowed to an activity wheel. Under these conditions, animals show a progressive increase in wheel running, a reduced efficiency in food intake to compensate for their increased activity, and a severe progression of weight loss. Due to the parallelism with the clinical manifestations of anorexia nervosa including increased activity, reduced food intake and severe weight loss, the ABA procedure has been proposed as the best analog of human anorexia nervosa (AN). Thus, ABA research could both allow a better understanding of the mechanisms underlying AN and generate useful leads for treatment development in AN.

Climate might be considered as a risk factor for anorexia nervosa? A hypothesis worth another look.

Environmental factors, such as ambient temperature m(AT), may have a causal role in the development of anorexia nervosa (AN), in addition to factors like the idealization of thinness. We present the literature and a bibliographic analysis that associate AN and a temperate climate.

Effect of auditory isolation on activity-based anorexia / Efecto del aislamiento auditivo en la anorexia basada en la actividad

The objective was to study male and female rats exposed to Activity-Based Anorexia (ABA; simultaneous exposition to food restriction and free access to an activity wheel) under two conditions of sound attenuation, by means of different arrangements of wheels (standard versus isolation) in the laboratory room. Regardless of the sound attenuation condition, all but one male and one female with access to wheels had to be removed from the experiment, but extended ABA endurance was found in rats in the sound attenuation condition. Furthermore, significantly lower levels of running were observed in both males and females under the sound attenuation arrangement in the isolation condition. The results suggest that external stimulation plays a role in the activity displayed by rats exposed to ABA, and that the reduction of external stimulation diminishes running but does not protect rats from developing ABA (AU)

El objetivo fue el estudio de ratas macho y hembra expuestas al procedimiento experimental de Anorexia basada en la Actividad (ABA, exposición simultánea a restricción de alimento y acceso libre a una rueda de actividad) bajo dos condiciones de atenuación acústica por medio de un arreglo experimental diferente de las ruedas de actividad (estándar versus aislamiento) en el laboratorio. Independientemente de la condición de la atenuación del sonido, todos los animales con acceso a las ruedas de actividad menos una rata macho y otra hembra tuvieron que ser retirados del experimento, mientras que la condición de atenuación del sonido aumentó la resistencia a ABA. Además, los niveles de actividad de machos y hembras fueron significativamente inferiores en la condición de atenuación del sonido en la condición de aislamiento. Los resultados sugieren que la estimulación externa desempeña un papel en la actividad desplegada por las ratas expuestas a ABA, y que aunque la reducción de la estimulación externa disminuye la actividad no protege a los animales del desarrollo de ABA (AU)

Hyperactivity in anorexia nervosa: warming up not just burning-off calories.

Excessive physical activity is a common feature in Anorexia Nervosa (AN) that interferes with the recovery process. Animal models have demonstrated that ambient temperature modulates physical activity in semi-starved animals. The aim of the present study was to assess the effect of ambient temperature on physical activity in AN patients in the acute phase of the illness. Thirty-seven patients with AN wore an accelerometer to measure physical activity within the first week of contacting a specialized eating disorder center. Standardized measures of anxiety, depression and eating disorder psychopathology were assessed. Corresponding daily values for ambient temperature were obtained from local meteorological stations. Ambient temperature was negatively correlated with physical activity (p = -.405) and was the only variable that accounted for a significant portion of the variance in physical activity (p = .034). Consistent with recent research with an analogous animal model of the disorder, our findings suggest that ambient temperature is a critical factor contributing to the expression of excessive physical activity levels in AN. Keeping patients warm may prove to be a beneficial treatment option for this symptom.

Effect of auditory isolation on activity-based anorexia.

The objective was to study male and female rats exposed to Activity-Based Anorexia (ABA; simultaneous exposition to food restriction and free access to an activity wheel) under two conditions of sound attenuation, by means of different arrangements of wheels (standard versus isolation) in the laboratory room. Regardless of the sound attenuation condition, all but one male and one female with access to wheels had to be removed from the experiment, but extended ABA endurance was found in rats in the sound attenuation condition. Furthermore, significantly lower levels of running were observed in both males and females under the sound attenuation arrangement in the isolation condition. The results suggest that external stimulation plays a role in the activity displayed by rats exposed to ABA, and that the reduction of external stimulation diminishes running but does not protect rats from developing ABA.

Heat makes a difference in activity-based anorexia: a translational approach to treatment development in anorexia nervosa.

OBJECTIVE: To test the effect of raising ambient temperature (AT) on activity-based anorexia (ABA) and to extend to female rats previous findings reported in male animals. METHOD: Two studies are reported in which female rats were submitted to food restriction and free access to an activity wheel either separately or in combination under changing (21-32 °C) or constant AT (21 °C). RESULTS: Warming ABA animals reversed running activity, preserved food-intake, and enabled female rats to recover from acute weight loss. Moreover, sedentary food-restricted warmed rats maintained a body weight equivalent to the levels of animals housed at standard AT in spite of 20% reduced food-intake. DISCUSSION: The replication on female rats corroborates the effect previously reported for males, which is indicative of the robust effect of AT in recovering rats from ABA. The findings reported here represent strong preclinical evidence in favor of heat supply as a useful adjunctive component for the treatment of anorexia nervosa (AN).

Gender dimorphic effects of voluntary running in laboratory rats depends on maturational status.

This study examined the effect of 24 hr per day wheel access on running, body weight, and food intake for 30- or 50-day-old male and female rats under ad lib feeding conditions. Food intake and body weight were also monitored in a control group housed without access to running wheels. A dimorphic effect was observed after wheel introduction in 50-day-old but not 30-day-old rats: A temporary decline in food intake and a lasting decrease in body weight occurred for active male rats in comparison to their sedentary controls, and wheel access facilitated food intake and preserved body weight gain in female rats in comparison to their sedentary counterparts. Hyperphagia in adult females is interpreted in terms of the evolutionary acquired advantage linked to their reproductive function.

Heat reversal of activity-based anorexia: implications for the treatment of anorexia nervosa.

OBJECTIVE: Activity-based anorexia (ABA) provides an animal model of anorexia nervosa (AN). In this model, rats given restricted access to food but unrestricted access to activity wheels, run excessively while reducing food intake, lose a sizeable percentage of body weight, become hypothermic, and can fail to recover unless removed from these conditions. METHOD: Once rats had lost 20% of body weight under standard ABA conditions, they were assigned to one of two ambient temperature (AT) conditions. RESULTS: Increased AT reduced running rates and led to weight gain in active rats. The effect of increasing AT on food intake was dependent on whether the rats were sedentary or active. Although warming reduced food intake in the sedentary rats their body weight remained stable, whereas in active rats increased AT did not reduce food intake and weight gain gradually rose. CONCLUSION: From a translational perspective, these findings offer a fresh perspective to the disorder, and underscore the need for further studies to assess the effects of heat treatment in patients as an innovative adjunctive treatment for anorexia nervosa.

High ambient temperature reduces rate of body-weight loss produced by wheel running.

This study examined the effect of ambient temperature (AT) on the relationship between activity and weight loss. Compared with a neutral AT of 21 degrees C, high ATs of 27-29 degrees C produced a slower rate of weight loss in rats given 1.5-hr food access and 22.5-hr running-wheel access in a standard activity-based anorexia (ABA) procedure (Experiments 1 and 2). The high AT did not affect food intake or wheel running in Experiment 1, but did reduce running in Experiment 2. Switching from neutral to high AT had only a transient effect on weight loss when wheel access was maintained (Experiment 2) but resulted in less weight loss when wheel access was prevented (Experiment 3). Giving rats only 3 hr of wheel access each day at a neutral AT also produced substantial weight loss, but less if for the rest of each day they were maintained at a high AT (Experiment 4).