East Coast Medical Director Dr. Molly McShane, MD, MPH is a board certified psychiatrist and practices psychotherapy and medication management for a range of psychiatric conditions including, but not limited to, depression, anxiety, trauma, ADHD, bipolar disorder, obsessive-compulsive disorder, PTSD, panic attacks, substance abuse and eating disorders. In part one of this two part series, Dr. McShane dives into the neurobiology and genetics of mental health disorders.
It is an exciting time in the world of brain and mental health research. Over the past few years, there has been an exponential increase in research findings in the neurobiology and genetics of mental health disorders. While we have known for decades that mental disorders are related to dysfunction in brain pathways, we are now able to say that mental illnesses are brain diseases.
Most diseases develop, progress and/or resolve due to a number of factors including biology, genetics, psychological co-morbidities and environmental exposures. Like most diseases, eating disorders typically occur in individuals with a genetic predisposition, meaning they are born with genes inherited from their parents, which are associated with eating disorders. Data shows that 50 to 80 percent of the risk of developing an eating disorder is related to genetics. Clinically, we know this. It is very common for my patients to tell me they have family members with eating disorder histories. In fact, first degree relatives of patients with eating disorders are over eleven times more likely to have anorexia nervosa compared to controls. There are over forty genes involved in the regulation of eating disorder behaviors, motivation, reward, personality traits and emotions. The relationship between the genes and environment is complex. These genes may be turned on or off by environmental triggers. Of course, environment (exposure to social media that over-emphasize image, involvement in certain activities like dance, modeling or wrestling, etc.) can play a significant role in the development of an eating disorder.
Certain temperaments are associated with the development of eating disorders. While specific genes have not yet been identified with temperament, we do know that temperament traits are often constant throughout life, before, during and after experiencing an eating disorder. The temperament traits commonly seen in individuals with eating disorders include harm avoidance, perfectionism, neuroticism, compulsivity, dysphoric mood, low self-directedness, impulsivity, sensation seeking, lack of planning and lack of persistence. Individuals with eating disorders may experience one or more of these temperament traits throughout life, while the eating disorder symptoms often change over time. It can be helpful to address the management of temperament traits in therapy.