P300 LATENCY IN GERIATRIC DEPRESSION

Objective: The purpose of this study was to determine if P300 latency is prolonged in geriatric depression and if longer P300 latency and de ficits in Initiation and errors of perseveration in depressed elderly patients are related to risk factors for vascular disease. Method: Ger iatric patients with unipolar depression (N=43) and elderly comparison subjects (N=24) were assessed for depressive symptoms, cognitive func tions, risk factors for vascular disease, and P300 latency. Results: D epressed elderly patients had longer P300 latency than normal elderly subjects. In the depressed patients, P300 latency was related to defic its in initiation and errors in perseveration. Risk factors for vascul ar disease were associated not only with P300 latency but also with de ficits in Initiation and errors in perseveration. Conclusions: Functio nal impairment of the cortico-striato-pallido-thalamo-cortical pathway s from vascular disease, implicated in late-life depressive disorders, may explain not only deficits in initiation and errors in perseverati on but also longer P300 latency in depressed elderly patients. These r esults are preliminary and need further examination with brain imaging and more sensitive neuropsychological measures.