Reduced Salience and Enhanced Central Executive Connectivity Following PTSD Treatment.

BACKGROUND

In soldiers with posttraumatic stress disorder (PTSD), symptom provocation was found to induce increased connectivity within the salience network, as measured by functional magnetic resonance imaging (MRI) and global brain connectivity with global signal regression (GBCr). However, it is unknown whether these GBCr disturbances would normalize following effective PTSD treatment.

METHODS

69 US Army soldiers with (n = 42) and without PTSD (n = 27) completed MRI at rest and during symptom provocation using subject-specific script imagery. Then, participants with PTSD received 6 weeks (12 sessions) of group cognitive processing therapy (CPT) or present-centered therapy (PCT). At week 8, all participants repeated the MRI scans. The primary analysis used a region-of-interest approach to determine the effect of treatment on salience GBCr. A secondary analysis was conducted to explore the pattern of GBCr alterations posttreatment in PTSD participants compared to controls.

RESULTS

Over the treatment period, PCT significantly reduced salience GBCr ( = .02). Compared to controls, salience GBCr was high pretreatment (PCT, = .01; CPT, = .03) and normalized post-PCT ( = .53), but not post-CPT ( = .006). Whole-brain secondary analysis found high GBCr within the central executive network in PTSD participants compared to controls. exploratory analyses showed significant increases in executive GBCr following CPT treatment ( = .01).

CONCLUSION

The results support previous models relating CPT to central executive network and enhanced cognitive control while unraveling a previously unknown neurobiological mechanism of PCT treatment, demonstrating treatment-specific reduction in salience connectivity during trauma recollection.