Frontal EEG asymmetry and symptom response to cognitive behavioral therapy in patients with social anxiety disorder.

Although previous studies have shown that socially anxious individuals exhibit greater relative right frontal electroencephalogram (EEG) activity at rest, no studies have investigated whether improvements in symptoms as a result of treatment are associated with concomitant changes in resting brain activity. Regional EEG activity was measured at rest in 23 patients with social anxiety disorder (SAD) before and after cognitive behavioral therapy (CBT). Results indicated that patients shifted significantly from greater relative right to greater relative left resting frontal brain activity from pre- to posttreatment. Greater left frontal EEG activity at pretreatment predicted greater reduction in social anxiety from pre- to posttreatment and lower posttreatment social anxiety after accounting for pretreatment symptoms. These relations were specific to the frontal alpha EEG asymmetry metric. These preliminary findings suggest that resting frontal EEG asymmetry may be a predictor of symptom change and endstate functioning in SAD patients who undergo efficacious psychological treatment.