A functional magnetic resonance imaging predictor of treatment response to venlafaxine in generalized anxiety disorder.
BACKGROUND
Functional magnetic resonance imaging (fMRI) holds promise as a noninvasive means of identifying neural responses that can be used to predict treatment response before beginning a drug trial. Imaging paradigms employing facial expressions as presented stimuli have been shown to activate the amygdala and anterior cingulate cortex (ACC). Here, we sought to determine whether pretreatment amygdala and rostral ACC (rACC) reactivity to facial expressions could predict treatment outcomes in patients with generalized anxiety disorder (GAD).


METHODS
Fifteen subjects (12 female subjects) with GAD participated in an open-label venlafaxine treatment trial. Functional magnetic resonance imaging responses to facial expressions of emotion collected before subjects began treatment were compared with changes in anxiety following 8 weeks of venlafaxine administration. In addition, the magnitude of fMRI responses of subjects with GAD were compared with that of 15 control subjects (12 female subjects) who did not have GAD and did not receive venlafaxine treatment.


RESULTS
The magnitude of treatment response was predicted by greater pretreatment reactivity to fearful faces in rACC and lesser reactivity in the amygdala. These individual differences in pretreatment rACC and amygdala reactivity within the GAD group were observed despite the fact that 1) the overall magnitude of pretreatment rACC and amygdala reactivity did not differ between subjects with GAD and control subjects and 2) there was no main effect of treatment on rACC-amygdala reactivity in the GAD group.


CONCLUSIONS
These findings show that this pattern of rACC-amygdala responsivity could prove useful as a predictor of venlafaxine treatment response in patients with GAD.
Whalen
Paul J
PJ
Department of Psychological and Brain Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA. paul.j.whalen@dartmouth.edu
Johnstone
Tom
T
Somerville
Leah H
LH
Nitschke
Jack B
JB
Polis
Sara
S
Alexander
Andrew L
AL
Davidson
Richard J
RJ
Kalin
Ned H
NH
D000328:Adult; D000679:Amygdala / Q000187:drug effects* / Q000503:physiopathology; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000503:physiopathology; D003511:Cyclohexanols / Q000009:adverse effects / Q000627:therapeutic use*; D003692:Delayed-Action Preparations; D005149:Facial Expression; D005239:Fear / Q000187:drug effects / Q000502:physiology; D005260:Female; D006179:Gyrus Cinguli / Q000187:drug effects* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010364:Pattern Recognition, Visual / Q000187:drug effects / Q000502:physiology; D017367:Selective Serotonin Reuptake Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome; D000069470:Venlafaxine Hydrochloride
D003511:Cyclohexanols; D003692:Delayed-Action Preparations; D017367:Selective Serotonin Reuptake Inhibitors; D000069470:Venlafaxine Hydrochloride