Brain-derived neurotrophic factor (BDNF Val66Met) in borderline personality disorder: Associated with eating disorder comorbidity but not psychotherapy response

Background

Brain-derived neurotrophic factor (BDNF) has been widely studied as a vulnerability factor for mental health disorders and is involved in learning and memory. We examined the association among the BDNF Val66Met genetic polymorphism (rs6265/G196A), risk for borderline personality disorder (BPD), and common co-morbidities of BPD (post-traumatic stress disorder (PTSD) and eating disorders (ED)). Furthermore, in this treatment study we were uniquely able to examine Val66Met in response to psychotherapy.

Methods

Data from 246 participants with BPD (82.1 % female, all white ancestry by self-report) were drawn from two randomized controlled trials. The association among BDNF Val66Met and comorbid ED and PTSD, as well as psychotherapy response was explored using chi-square analyses. The distribution of BDNF Val66Met in our BPD sample was also compared to the general population using the 1000 Genomes sample (n = 370).

Results

Carrying the Met allele was associated with a 1.9-fold [95 % CI:1.12–3.19] increased risk of having an ED (p = 0.017) and, specifically, a 2.5-fold [95 % CI:1.15–5.56] increased risk of having anorexia nervosa (p = 0.018). The Met allele was not associated with PTSD comorbidity or psychotherapy response. No significant difference was found between our BPD sample versus the general white population (p > 0.50).

Conclusion

In keeping with previous literature, carrying the Met allele was associated with increased risk of ED, particularly AN, among BPD individuals. Val66Met was not associated with BPD, comorbid PTSD, or psychotherapy response. Further studies, in larger and more diverse samples, incorporating other genes and modifications in the BDNF pathway, are warranted.