Ventral striatal activation during reward differs between major depression with and without impaired mood reactivity

Background: Recent efforts to classify subtypes of major depressive disorder marked by different psychophysiological indicators have identified blunted reward-related brain activation in gambling tasks as a characteristic linked specifically to depressed participants with impaired mood reactivity. Methods: The current study compared individuals diagnosed with current depressive disorder (n = 26) with healthy controls (n = 24) regarding brain responses to gain and loss trials in an fMRI version of the "Doors" choice-feedback task. Study aims were to examine reward-related brain activation in relation to depression, depressive subtypes, and course of depression. Results: Across the sample, participants showed a significant response to gain versus loss in left and right ventral striatum as well as medial and left lateral prefrontal cortex. Relative to controls, participants with current depression were characterized by blunted reactivity in left ventral striatum. Furthermore, activation in the left ventral striatum differentiated subgroups of depression with and without impaired mood reactivity. Finally, left striatal hypoactivation to reward predicted remission when controlling for current depressive symptomatology, albeit at a trend level. Conclusions: Blunted reward-related activation in the left ventral striatum might be useful as a marker for depression subtype and may have the potential to predict future course of depression.