Changes in medial prefrontal cortex neural responses parallel successful antidepressant combination of venlafaxine and light therapy.

Few pilot prospective studies performed BOLD fMRI before and after treatment in order to define the neural correlates of antidepressant response. To determine how antidepressant treatment influences the pattern of neural response to a task targeting the depressive biases in information processing (moral valence decision), eight depressed inpatients were treated with combined venlafaxine and light therapy for four weeks. Brain BOLD functional magnetic resonance imaging on a 3.0 Tesla scanner was performed before and after treatment. Treatment and moral value of the stimuli showed the most significant interaction in right medial frontal gyrus (BA 10), where also clinical status was found to be inversely correlated with response to negative stimuli after treatment. A significant interaction of treatment and valence of the stimuli was also detected in other areas that have been widely associated with the depressive illness.