14 DAY TRIAL // Bulimia acts insidiously on the human brain, by hindering the correct firing of neurons in the cortex's reward circuitry. As such, people who suffer from the condition do not experience the correct rewards provided by the neurotransmitter dopamine when reward-worthy actions are completed.
This is one of the first studies that shows how this severe eating disorder is physically affecting the brain of patients. In order to carry out this study, experts used a group of women who were diagnosed with the condition, and analyzed their performances versus those of healthy women in a control group.
Primarily, the research effort focused on studying how the women acted and performed when faced with a learning task reinforced by a reward. The experiment was carefully set up so that the dopamine-based reward circuitry of the brain was activated every single time.
The reason why dopamine is such a critical chemical for humans is because it plays tremendously important roles in regulate behaviors such as learning and motivation. As such, any malfunction affecting the system this neurotransmitter uses can have widespread ramifications.
Bulimia nervosa is a disorder that can lead to extreme, weight-related manifestation, such as for example extreme, exhausting workouts, use of laxatives and self-induced vomiting. The condition affects women more often the men.
When put through the lab task, the brains of women with bulimia nervosa exhibited considerably lower levels in the dopamine circuits than the cortices of healthy individuals did. The new investigation was led by University of Colorado in Denver expert Guido Frank, MD, PsychCentral reports.
The investigator found that the frequency of binge/purge episodes was directly related to the level of neural activity in the dopamine system, in the brains of bulimia patients. The more episodes the women put themselves through, the lower their dopamine activity levels were found to be.
“This is the first study that suggests that brain dopamine-related reward circuitry, pathways that modulate our drive to eat, may have a role in bulimia nervosa. That is, the more often an individual has binge/purge episodes, the less responsive is the brain,” Frank explains.
“That suggests that the eating disorder behavior directly affects brain function. These findings are important since the brain dopamine neurotransmitter system could be an important treatment target for bulimia nervosa,” the investigator goes on to say.
Frank holds an appointment as an assistant professor in the departments of Psychiatry and Neuroscience at UCD, and is also the director of the Developmental Brain Research Program at the university's Anschutz Medical Campus.
Details of the new work were published in the latest issue of the esteemed medical journal Biological Psychiatry.