RecruitingDevice studyElectroconvulsive Therapy (ECT) for Agitation in Dementia (AD)This study will explore the effect of ECT treatments plus usual care (ECT+UC) in reducing severe agitation in patients with moderate to severe dementia including Alzheimer's Disease, Vascular dementia, Frontotemporal dementia, and Dementia with Lewy Bodies. The study will also determine the tolerability/safety outcomes of ECT+UC.