Electroconvulsive Therapy is a highly effective treatment for severe or treatment-resistant depression, especially when rapid symptom relief is needed for suicidality, psychosis, or catatonia. It involves applying brief electrical currents to the scalp under general anesthesia, intentionally inducing a controlled seizure that resets abnormal brain activity. Treatments are typically administered 2–3 times per week for 6–12 sessions. ECT achieves response rates of 70–90%, making it the most effective acute therapy for major depression. Common side effects include short-term memory loss, confusion, and headache, but serious complications are rare with modern techniques.