The basic variations in brain anatomy between those with and without anorexia nervosa have been discovered by a team of neuroscientists from the University of Bath (UK) and international partners. Anorexia is a severe eating disorder and mental health illness that affects approximately a quarter of a million people in the United Kingdom aged 16 and over. Experts say the symptoms are caused by people trying to lose weight as quickly as possible by not eating enough.
What does the neurobiological research say about Anorexia Nervosa?
The brain areas, biological origins of symptoms, and neurochemical variations between anorexia patients and healthy controls are all studied in neurobiological research. In anorexia, severe weight loss induces a loss of grey matter in various locations of the brain. Furthermore, abnormalities in the amygdala, basal ganglia regions and hippocampus have been revealed in neuro-imaging studies reviewing PET, MRI, and fMRI. Evidence also suggests that the dopaminergic and serotonergic (5-HT) systems, which are involved in hunger, motivation, reward, executive function, mood regulation, and impulse control, become dysfunctional in this condition. As a result, food, which serves as a natural reward, becomes a source of both threat and anxiety.
While patients were looking at pictures of the food, an increase in amygdala activity (threat perception) and a decrease in inferior parietal lobe activity (food-related pleasure and interest) were observed in one fMRI study. Anorexia patients respond to body-related phrases and images differently than controls. They focus on these words and pictures, paying attention to body parts rather than the overall body; also, when they look at their own body, they have cognitive, perceptual, and emotional alterations. This can be explained by the decrease in occipital and prefrontal brain activity.
Why some people acquire anorexia while others do not is still a mystery
The findings of the research study examining the biological aspects appeared in the journal Biological Psychiatry. The researchers discovered that individuals suffering from anorexia have significant reductions in three key brain measures, cortical thickness, subcortical volumes, and cortical surface area. Since they are supposed to indicate the loss of brain cells or their connections, results showing smaller brains become crucial. The findings clearly reveal correlations between anatomical alterations in the brain and eating disorders. The effect of sizes in their anorexia study is the largest of any psychiatric condition studied so far, according to the researchers. This implies that anorexia patients have brain size and shape reductions that are 2 to 4 times bigger than people with depression, ADHD, or OCD. Researchers mentioned that reductions in people’s body mass index (BMI) may be to blame for alterations in brain size reported in anorexia patients.
Reductions in brain structure were less severe in those recovering from anorexia
The researchers pooled over 2,000 pre-existing brain scans of individuals with anorexia, including those in recovery and healthy controls. The study discovered that reductions in brain structure were less severe in those recovering from anorexia. This could imply that the brain can heal itself if given the right treatment and assistance at the right time..png)
Dr. Esther Walton, Lead Researcher, Department of Psychology, University of Bath revealed that they collaborated with research teams from all over the world for several years for this study. They were able to analyze the brain abnormalities that potentially characterize anorexia in greater depth thanks to the ability to combine thousands of brain scans. The large decreases in brain structure that they saw in patients were less visible in patients who were recovering. She stated that it is a positive indicator because it implies that the modifications aren’t permanent, and the brain would recover with the appropriate treatment.
Academics from The Technical University of Dresden, Germany, the Icahn School of Medicine at Mount Sinai in New York, and King’s College London were also part of the research team. The researchers collaborated as part of the University of Southern California’s ENIGMA Eating Disorders Working Group to better understand the link between brain anatomy, function, and mental health. The ENIGMA Consortium is a multinational collaboration of imaging genetics, neurology, and psychiatric experts.
