Background: Affective facial processing is an important component of interpersonal relationships. The neural substrate has been examined following treatment with antidepressant medication but not with psychological therapies. The present study investigated the neural correlates of implicit processing of sad facial expressions in depression pretreatment and posttreatment with cognitive behavioral therapy (CBT).
Methods: The patient group consisted of 16 medication-free subjects (mean age 40 years) with a DSM-IV diagnosis of acute unipolar major depression, and the comparison group were 16 matched healthy volunteers. Subjects participated in a prospective study with functional magnetic resonance imaging (fMRI) at weeks 0 and 16. During the fMRI scans, subjects performed an affect recognition task with facial stimuli morphed to display varying intensities of sadness. Patients received 16 sessions of CBT. Functional magnetic resonance imaging data were analyzed for the mean activation and differential response to variable intensity (load-response) of facial affect processing.
Results: During an acute depressive episode, patients showed elevated amygdala-hippocampal activity relative to healthy individuals. Baseline dorsal anterior cingulate activity in patients showed a significant relationship with subsequent clinical response.
Conclusions: These data provide further support for elevated amygdala activity in depression and suggest that anterior cingulate activity may be a predictor of treatment response to both pharmacotherapy and CBT.