Amygdala response in patients with acute PTSD to masked and unmasked emotional facial expressions

Objective: This study used functional magnetic resonance imaging to investigate amygdala response in patients with acute posttraumatic stress disorder (PTSD) to emotional expressions. Method: Thirteen medication-free individuals with acute PTSD and no axis I psychiatric comorbidity were scanned while viewing pictures of fearful or happy faces, presented above or below consciousness, with backward masking. Results: There was a significant positive correlation between the severity of PTSD and the difference in amygdala responses between masked fearful and happy faces and a corresponding negative correlation for the difference between unmasked fearful and happy faces. Conclusions: These findings suggest that functional abnormalities in brain responses to emotional stimuli observed in chronic PTSD are already apparent in its acute phase.