Electrophysiological activity underlying inhibitory control processes in late-life depression: a Go/Nogo study.

Late-life depression is characterized by the coexistence of affective disorder and executive impairment. We investigated the neural correlates of inhibitory control processing in people with late-life depression using event-related potentials (ERPs). A visual Go/Nogo task was employed. A larger Nogo-N2 and Nogo-P3 was found in the depressed group compared to the control group. This reflects the non-physiological process of conflict monitoring and inhibitory control in depressed patients. The results also showed that the difference wave between Go and Nogo conditions (Pd3) over the frontal electrode sites was more robust and earlier in the control group compared to the depressed group, which reflects frontal dysfunction in the depressed group. Also in the depressed subject a significant correlation between the 17-item Hamilton rating scale for depression (HRSD-17) and the amplitudes of Nogo-N2 and Pd3 was found. Our results imply that the Nogo-N2, Nogo-P3 and Pd3 features can be considered as endophenotypic markers of the late-life depression.