Background: A deficit in the ability to inhibit fear may be a specific biomarker of post-traumatic stress disorder (PTSD). Previous research indicates that individuals with PTSD show reduced inhibition-related activation in rostral anterior cingulate cortex (rACC), but it is unclear whether this is a risk factor or acquired feature of the disorder. The objective of the study was to investigate the influence of an early environmental risk factor for PTSD – childhood maltreatment – on inhibition-related brain function.
Methods: Individuals with PTSD and traumatized controls recruited from the Grady Trauma Project completed an inhibition task during fMRI, and reported childhood and adult traumatic experiences. After excluding data for motion artifacts, brain abnormalities, and low task performance, 37 individuals with PTSD and 53 traumatized controls were included in the final analyses. The groups were matched for adult and child trauma load.
Results: There was an interaction between childhood maltreatment severity and PTSD status in rACC (p<.05, corrected), such that maltreatment was negatively associated with inhibition-related rACC activation in the PTSD group only. Rostral ACC activation was associated with inhibition-related task performance in the TC group but not the PTSD group, suggesting that inhibition-related activity in this region may contribute to stress resilience.
Conclusions: Findings indicate that child maltreatment presents an early and long-lasting influence on inhibition-related activity in the rACC, which may promote or protect against PTSD.