The influence of the BDNF Val66Met genotype on emotional recognition memory in post-traumatic stress disorder

Dysregulated consolidation of emotional memories is a core feature of posttraumatic stress disorder (PTSD). Brain Derived Neurotrophic Factor (BDNF) influences synaptic plasticity and emotional memory consolidation. The BDNF Val66Met polymorphism has been associated with PTSD risk and memory deficits respectively, although findings have been inconsistent, potentially due to a failure to control for important confounds such as sex, ethnicity, and the timing (child/adult) and extent of previous trauma experiences. Furthermore, very little research has examined the impact of BDNF genotypes on emotional memory in PTSD populations. This study investigated the interaction effects of the BDNF Val66Met genotype and PTSD symptomatology in an emotional recognition memory task in 234 participants. Key findings revealed impaired negative recognition memory in PTSD (n=44) compared to Control (n=85) and trauma exposed (n=105) groups and in participants with the Val/Met compared to the Val/Val genotype. There was a group x genotype interaction driven by the lack of impairment in the TE group with the Val/Met genotype. Results suggest that people previously exposed to trauma who do not develop PTSD may be protected from the BDNF Met effect, however more research is needed to replicate findings and to explore the relevant epigenetic and neural processes involved.