By Margarita Nahapetyan
A new study carried out by a team of experts from Columbia University and New York State Psychiatric Institute shows that women with eating disorder are way more impulsive than healthy women. The study was published in January's edition of the Archives of General Psychiatry, one of the JAMA/Archives journals.
Rachel Marsh, an assistant professor of clinical psychology in the division of child and adolescent psychiatry at Columbia University in New York City and her colleagues compared 20 women with bulimia and 20 women without eating disorder(the women's ages and BMI were similar in both groups) using the Simon Spatial Incompatibility test, in which participants needed to show the direction in which an arrow was pointing regardless of its location on the screen. In the test, the arrows appeared and disappeared quickly, therefore participants' scores were based on accuracy and speed. Functional Magnetic Resonance Imaging recorded the women's brain activity as they did the test and showed that in women with disorder, the frontostriatal circuits (which help people regulate their behavior) did not function in a proper way. The women with bulimia nervosa turned out to respond much faster and made more errors. And even after committing an error, they would still immediately go on to make another unforced error for the same reasons. And the women suffering from the most severe bulimia symptoms had the worst test results. "When individuals are performing correctly, they need to engage self-regulatory control or cognitive control. They need to hold back the automatic response strategy in order to perform correctly" Rachel Marsh explained.
Bulimia nervosa typically begins in the late adolescence or early 20s and primarily affects girls and women. Unlike anorexia, where patients bring almost to minimum the amount of food they eat, patients with bulimia do not control and restrict themselves in eating which leads to self-induced vomiting, use of laxatives, fasting, enemas, diuretics, excessive exercising or another compensatory behavior to avoid weight gain. The condition is often followed by other serious mental health problems such as obsessive-compulsive disorder, depression, and anxiety and can be potentially life-threatening. Experts believe these episodes of binge eating are associated with a severe sense of loss of control.
Researchers are only in the early stages of beginning to understand the cause and effects of bulimia and other eating disorders. There are strong suspicions among them that bulimia nervosa may have a genetic association and previous study has suggested that low levels of the brain chemicals serotonin and dopamine, the key neurotransmitters, may be involved. So far, serotonin has been widely implicated in bulimia, which is often treated with antidepressants known as selective serotonin reuptake inhibitors (SSRIs). However, dopamine has not been studied closely in relation to bulimia nervosa."It might be a godsend to discover that patients are genetically pre-programmed, but it could also make people feel hopeless and that they have no control of the disorder," said one of the experts. Future studies and research are being suggested to determine if the abnormality happens as a result of having bulimia nervosa or if having the abnormality contributes to the development of the condition. Future studies should also include impulsive individuals who have healthy weights and eating behaviors, adolescents close to the time that bulimia nervosa develops and patients with varying severity of symptoms.
The mystery of how and why bulimia nervosa occurs has still to be untangled but its cause has been linked to socio-cultural issues and a desire to be thin. The treatment of bulimia is complex as most of the patients require a combination of psychotherapy, antidepressants and nutritional therapy. The eating disorder is challenging and many sufferers from bulimia are not able to fully recover in spite of a constant and maximum therapy. "Patients are often reluctant to take medication such as antidepressants but if they know doctor is recommending medication because their brain is not working right, it will help convince them," says associate Professor Michael Kohn, co-director of the Eating Disorders Service at the Children's Hospital at Westmead. Patients should be aware of the possibility that cycles of binge eating and self-induced vomiting may occur from time to time throughout their lives. To prevent re-occurrence, it is very important that people learn how to handle their body image, how to develop strong and healthy family relationships and how to manage stress in an effective way.
The study was supported and partly granted by the National Institute of Mental Health, the National Alliance for Research on Schizophrenia and Depression, and the Sackler Institute for Developmental Psychobiology at Columbia University.