By JESSICA BAKER
Published: September 5, 2013
I started as a postdoctoral fellow at the UNC Center of Excellence for Eating Disorders in 2010 and officially complete the fellowship this month. Luckily, I have been offered the opportunity to stay at CEED as a faculty member, so I won’t be going anywhere! Since my postdoctoral fellowship is wrapping up, I thought this would be a perfect time to write a blog about some of the research projects I’ve spearheaded. My general research interests in the eating disorders field include identifying the genetic and biological risk factors for eating disorders, with a specific interest in reproductive hormones like estrogen; and the comorbidity between eating disorders and substance use disorders. I’ve been able to focus on both of these interests during my fellowship. Below, I briefly summarize the three main empirical projects I’ve lead as a postdoc that have been published.
Shared Genetic Effects Between Age at Menarche and Disordered Eating
We know that adolescence is a risk factor for the development of eating disorders, and that an early age of menarche (a girl’s first period) is also associated with an increased risk for eating disorder behavior in females . Because of these connections, I was interested in examining whether age at menarche and disordered eating share genetic factors, in other words do the same genetic factors influence age at menarche and aspects of disordered eating? Results suggested that indeed, some of the genetic factors that influence a younger age at menarche are shared with the genetic factors that influence increased risk for disordered eating. Although these findings are informative, we were unable to determine what precise genetic factors or biological systems are actually involved in the genetic overlap between age at menarche and disordered eating. I am very much interested in pursuing this further and determining what factors might account for this overlap, for example the estrogen system.
Baker, J. H., Thornton, L. M., Bulik, C. M., Kendler, K. S., & Lichtenstein, P. (2012). Shared genetic effects between age at menarche and disordered eating. Journal of Adolescent Health, 51, 491-496.
Pubertal Development Predicts Eating Behaviors in Adolescence
As I described above, girls who reach puberty at an early age are at increased risk for an eating disorder. However, it is unknown whether the increased risk for disordered eating during puberty is restricted to when pubertal development is happening or if it continues to increase risk throughout development. For example, does age of pubertal onset continue to increase risk for an eating disorder throughout young adulthood? Or does it only increase risk during adolescence, when pubertal development is typically happening? It is also not clear if puberty is associated with increased risk for disordered eating in boys. Therefore, I examined whether pubertal development predicts disordered eating in adolescence and young adulthood in girls and boys. We found that pubertal development during early adolescence significantly predicted disordered eating and dieting in late adolescence for both boys and girls. However, it did not predict any aspects of disordered eating in young adulthood. This would suggest that pubertal development may only play a role in risk for eating disorders during puberty.
Temporal Sequence of Comorbid Alcohol Use Disorder and Anorexia Nervosa
Women with eating disorders are much more likely to also have an alcohol use disorder compared with women in the general population. However, there is a fundamental “chicken and the egg” problem. It is unclear which disorder tends to develop first and if there are differences in risk factors for each disorder. In addition, it is uncertain whether eating disorder symptoms are the same in women who develop an eating disorder first versus women who develop an alcohol use disorder first. To address these questions, I explored the temporal pattern of comorbid anorexia nervosa and an alcohol use disorder, specifically looking at differences between three groups: women with anorexia only; women with both disorders who developed AN first; and women with both disorders who developed an alcohol disorder first. Results suggested that women with binge eating or purging type anorexia were more likely to have an alcohol use disorder and that women with both disorders showed higher scores on a measure of impulsivity, were more likely to be depressed, and to have borderline personality disorder. However, the actual nature of the eating disorder was no different if it came first or second.
Baker, J. H., Thornton, L. M., Strober, M., Brandt, H., Crawford, S., Fichter, M. M., … Bulik, C. M. (2013). Temporal sequence of comorbid alcohol use disorder and anorexia nervosa. Addictive Behaviors, 38, 1704-1709.
I am glad that I have been able to answer some of these important questions while a fellow at CEED. I look forward to many more years with the center and will continue to explore my areas of interest above in future research!