fMRI Response to Facial Expression in Adolescent PTSD.

Introduction

fMRI studies often present trauma-related stimuli to adults. Greater amygdala responses to fearful faces have been seen in subjects with PTSD compared with controls.

Evidence for involvement of medial frontal cortex and anterior cingulate have been consistently found.

Method

During fMRI scanning, 8 adolescents with PTSD (average age 14.2 years) and 8 control subjects (average age 15.4 years) were asked to rate photographs of happy, sad, angry, or fearful faces, alternated with scrambled (neutral) photographs during an fMRI scan.

Results

Happy/Sad

Controls show greater overall activation than subjects with PTSD. Controls show activation in amygdala in response to happy and sad faces (circles).

Control: happy-scrambled	Control: sad-scrambled

Subjects with PTSD show little or no activation in amygdala in response to happy and sad faces.

PTSD: happy-scrambled	PTSD: sad-scrambled

Anger/Fear

Controls show activation of amygdala in response to angry and fearful faces.

Control: angry-scrambled	Control: fear-scrambled

Subjects with PTSD show show activation of amygdala to fearful and angry faces (circles).

PTSD: angry-scrambled	PTSD: fear-scrambled

Unlike control subjects, those with PTSD show amygdala activation only in response to fearful or angry faces. In medial frontal/anterior cingulate and orbital-frontal regions, subjects with PTSD show activation only in response to angry faces.

Conclusions

In response to happy and sad faces, control subjects activate the medial frontal and anterior cingulate cortex more than subjects with PTSD.

Control subjects respond to all emotions in faces with amygdala activation, while subjects with PTSD show amygdala activation only to fearful and angry faces, a result found in other studies with PTSD subjects.

Subjects with PTSD have greater activation than controls to angry faces in the orbital frontal cortex.

These results suggest that subjects with PTSD have decreased emotional responses to happy and sad faces, and relatively increased responses to fearful and angry faces.