Correlation Between Rostral Dorsomedial Prefrontal Cortex Activation by Trauma-Related Words and Subsequent Response to CBT for PTSD

Trauma-focused cognitive-behavioral therapy (CBT) is an important component of evidence-based treatment for posttraumatic stress disorder (PTSD), but the efficacy of treatment varies from individual to individual. It is hypothesized that some of this variability is derived from interindividual differences in the brain’s intrinsic response to trauma-related stimuli and in activity of executive functional regions. The authors sought to characterize these differences using functional MRI (fMRI) in patients about to undergo CBT for PTSD.

Blood-oxygenation-level-dependent signal was measured in 12 individuals with PTSD related to sexual and/or physical trauma while they read words with positive, neutral, and negative content. Some negative words had PTSD-related themes, while others did not. It was hypothesized that PTSD-related words would evoke emotional processes likely to be engaged by the CBT process and would be most likely to activate brain circuitry important for CBT success.

A group-level analysis showed that the rostral dorsomedial prefrontal cortex (rdmPFC) was activated to a greater degree in response to PTSD-related words compared with other word types. This activation was strongest among patients with the best CBT responses, particularly in the latter part of the task, when differences between individuals were most pronounced.

The rdmPFC activation observed in this study may reflect the engagement of neural processes involved in introspection and self-reflection. CBT may be more effective for individuals with a greater ability to engage these processes.