Amygdala and ventral anterior cingulate activation predicts treatment response to cognitive behaviour therapy for post-traumatic stress disorder.
BACKGROUND
Although cognitive behaviour therapy (CBT) is the treatment of choice for post-traumatic stress disorder (PTSD), approximately half of patients do not respond to CBT. No studies have investigated the capacity for neural responses during fear processing to predict treatment response in PTSD.


METHODS
Functional magnetic resonance imaging (fMRI) responses of the brain were examined in individuals with PTSD (n=14). fMRI was examined in response to fearful and neutral facial expressions presented rapidly in a backwards masking paradigm adapted for a 1.5 T scanner. Patients then received eight sessions of CBT that comprised education, imaginal and in vivo exposure, and cognitive therapy. Treatment response was assessed 6 months after therapy completion.


RESULTS
Seven patients were treatment responders (defined as a reduction of 50% of pretreatment scores) and seven were non-responders. Poor improvement after treatment was associated with greater bilateral amygdala and ventral anterior cingulate activation in response to masked fearful faces.


CONCLUSIONS
Excessive fear responses in response to fear-eliciting stimuli may be a key factor in limiting responses to CBT for PTSD. This excessive amygdala response to fear may reflect difficulty in managing anxiety reactions elicited during CBT, and this factor may limit optimal response to therapy.
Bryant
R A
RA
School of Psychology, University of New South Wales, Sydney, NSW, Australia. r.bryant@unsw.edu.au
Felmingham
K
K
Kemp
A
A
Das
P
P
Hughes
G
G
Peduto
A
A
Williams
L
L
D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001143:Arousal / Q000502:physiology; D015928:Cognitive Behavioral Therapy; D003887:Desensitization, Psychologic; D004292:Dominance, Cerebral / Q000502:physiology; D005149:Facial Expression; D005239:Fear / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000502:physiology*; D013313:Stress Disorders, Post-Traumatic / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome