This study looks at how well Electroconvulsive Therapy (*ECT*) works to reduce severe agitation in people with moderate to severe dementia, like Alzheimer's or Vascular dementia. Agitation is when someone becomes really restless or upset. ECT is a treatment where small electrical currents are passed through the brain to help improve symptoms. This study also checks if ECT is safe and if its effects last over time. About 50 people will join, and they will have at least one ECT session. After that, they will be observed for 12 months to see how they do.

• Participants must be 40 years or older and have severe agitation from dementia.
• Participants should have tried at least one medicine for their behavior without success.
• The study lasts for at least 12 months, with follow-up visits.