Girls with anorexia have increased neural activation to fearful faces

A recent neuroimaging study of adolescent females with anorexia nervosa reported increased neural activation in the somatomotor cortex when viewing fearful faces following short-term weight recovery. There were no differences in reactivity to neutral, angry, or surprised faces. The paper was published in Psychiatry Research: Neuroimaging.

Anorexia nervosa is a serious eating disorder characterized by an intense fear of gaining weight, a distorted body image, and extreme restriction of food intake. People with anorexia tend to perceive themselves as overweight even when they are underweight. They often engage in excessive dieting, fasting, or compulsive exercise to lose weight.

The condition can lead to severe malnutrition, muscle wasting, heart problems, and other life-threatening complications. Psychological factors, such as perfectionism, low self-esteem, and anxiety disorders, also contribute to its development. Without proper intervention, anorexia has one of the highest mortality rates among psychiatric disorders due to complications like organ failure and suicide.

Study author Lukas Stanetzky and his colleagues noted that problems with emotion recognition and regulation might play an important role in anorexia. Anxiety disorders occur in approximately two out of three patients with anorexia and worsen long-term outcomes. These anxiety symptoms tend to decrease after individuals with anorexia restore some weight.

To better understand the role of emotion recognition and regulation in anorexia, the authors conducted a neuroimaging study examining brain activation in individuals with anorexia when exposed to pictures of faces displaying different emotions. They compared these neural responses to those of healthy individuals.

The study included 22 adolescent girls with anorexia nervosa recruited from the Department of Child and Adolescent Psychiatry, Psychosomatics, and Psychotherapy at University Hospital RWTH Aachen, Germany. These participants underwent neuroimaging once after admission during acute starvation (caused by anorexia) and a second time after discharge following short-term weight restoration (i.e., after regaining some of the weight lost). The control group consisted of 27 healthy participants recruited from local high schools around Aachen.

Participants completed assessments for eating disorders (using the Eating Disorder Inventory 2), depression, and anxiety. They also underwent functional magnetic resonance imaging while performing a face-matching task. In this task, participants were shown sets of human faces expressing fear, surprise, anger, or neutrality, and they were asked to select, from two faces presented, the one that matched the target face.

The results showed that participants with anorexia exhibited significantly increased neural activation in the somatomotor cortex when viewing fearful faces after weight recovery (at the time of discharge). There were no differences in neural reactions to angry, neutral, or surprised faces.

“Higher somatomotor activity could represent anxiety-induced preparations for motor reactions (e.g., fight or flight) that are more pronounced in more affected patients. These results align with recent models of AN [anorexia nervosa] that increasingly incorporate anxiety into the pathophysiological and prognostic model of AN and help elucidate its underlying neurological mechanisms,” study authors concluded.

The study sheds light on the neural underpinnings of anorexia nervosa in adolescent girls. However, it should be noted that the study design does not allow for any causal inferences to be drawn from the data. Therefore, it remains uncertain whether the changes in neural activation patterns are a consequence of weight gain, a result of anorexia nervosa, or caused by some other factor not included in the study.

The paper, “Longitudinal changes in neural responses to fearful faces in adolescents with anorexia nervosa – A fMRI study,” was authored by Lukas Stanetzky, Arne Hartz, Kimberly Buettgen, Brigitte Dahmen, Beate Herpertz-Dahlmann, Kerstin Konrad, and Jochen Seitz.