The Shift of EEG Activity in SAD Patients Treated with CBT

Researchers are investigating the neurological effects of therapeutic interventions on patients with a variety of disorders, including PTSD, but few studies have focused on the neurological effects of CBT on patients with Social Anxiety Disorder (SAD).  Emotional processing occurs in both sides of the frontal brain.  The right area of the frontal brain is associated with negative emotions and the left area with positive emotions.  The present study uses this frontal brain asymmetry in hopes of observing the effects of cognitive behavior therapy on the neural mechanisms of patients with SAD.   Researchers believe that patients with SAD should have more EEG activity in the right frontal pretreatment, which would shift to the left frontal brain post treatment.

23 outpatients with SAD were recruited to participate in this study.  All participants underwent 12, two-hour long group CBT sessions.  Each group had 7 to 9 patients and 2 to 3 qualified therapists following a protocol manual.  About two weeks before the first session and again after the last session, participants underwent a 6 minute EEG assessment.  At each assessment, participants were also asked to complete the Social Phobia Inventory (SPIN) and the Beck Depression Inventory (BDI-II).

The results indicated a significant decrease in SAD severity, as well as decreased self-reported measures of the SPIN and BDI-II post treatment.  The study also yielded a shift in the EEG activity from the right side of the frontal brain to the left, demonstrating a shift of emotional processing from the negative to the positive.  Moscovitch et al noted that higher activity in the left frontal brain pretreatment correlated with lower social anxiety and depression scores post treatment.  These findings suggest that the effects of CBT can be measure biologically.  Future studies may also find EEG assessments useful in predicting a patient’s response to CBT.

Moscovitch, D. A., Santesso, D. L., Miskovic, V., McCabe, R.E., Antony, M.M., & Schmidt, L. A.  (2011). Frontal EEG asymmetry and symptom response to cognitive behavioral therapy in patients with social anxiety disorder.  Biological Psychology.  (in press)