Antidepressant treatment normalizes hypoactivity in dorsolateral prefrontal cortex during emotional interference processing in major depression

Background: Major depression (MDD) is characterized by altered emotion processing and deficits in cognitive control. In cognitive interference tasks, patients with MDD have shown excessive amygdala activity and under-recruitment of dorsolateral prefrontal cortex (DLPFC). The purpose of this study was to examine the effects of antidepressant treatment on anomalous neural activity in cognitive-control and emotion-processing circuitry. Methods: Functional magnetic resonance imaging was conducted on depressed patients (n = 23) (both before and after antidepressant treatment) compared with matched controls (n = 18) while they performed a cognitive task involving attended and unattended fear-related stimuli. Results: After eight weeks of SSRI antidepressant treatment, patients with depression showed significantly increased DLPFC activity to unattended fear-related stimuli and no longer differed from controls in either DLPFC or amygdala activity. Conclusions: These results suggest that antidepressant treatment increases DLPFC under-activity during cognitive tasks that include emotional interference. Limitations: The sample was fairly homogeneous and this may limit generalizability.