The Neurobiological Role of the Dorsolateral Prefrontal Cortex in Recovery From Trauma

Abstract

CONTEXT: A multiwave longitudinal neuroimaging study in a cohort of direct survivors of a South Korean subway disaster, most of whom recovered from posttraumatic stress disorder 5 years after trauma, provided a unique opportunity to investigate the brain correlates of recovery from a severe psychological trauma. OBJECTIVES: To investigate region-specific brain mobilization during successful recovery from posttraumatic stress disorder by assessing cortical thickness multiple times from early after trauma to recovery, and to examine whether a brain-derived neurotrophic factor gene polymorphism was associated with this brain mobilization. DESIGN: Five-year follow-up case-control study conducted from 2003-2007. SETTING: Seoul National University and Hospital. PARTICIPANTS: Thirty psychologically traumatized disaster survivors and 36 age- and sex-matched control group members recruited from the disaster registry and local community, respectively, who contributed 156 high-resolution brain magnetic resonance images during 3 waves of assessments. MAIN OUTCOME MEASURES: Cerebral cortical thickness measured in high-resolution anatomic magnetic resonance images using a validated cortical thickness analysis tool and its prospective changes from early after trauma to recovery in trauma-exposed individuals and controls. RESULTS: Trauma-exposed individuals had greater dorsolateral prefrontal cortical (DLPFC) thickness 1.42 years after trauma (right DLPFC, 5.4%; left superior frontal cortex, 5.8%; and left inferior frontal cortex, 5.3% [all clusters, P ≤ .01]) relative to controls. Thicknesses gradually normalized over time during recovery. We found a positive linear trend, with trauma-exposed individuals with a valine/valine genotype having the greatest DLPFC cortical thickness, followed by those with a methionine genotype and controls (P < .001 for trend). Greater DLPFC thickness was associated with greater posttraumatic stress disorder symptom reductions and better recovery. CONCLUSION: The DLPFC region might play an important role in psychological recovery from a severely traumatic event in humans.