ECT involves passing a precisely calculated electric current through the brain to produce brief, controlled seizures. It's used only in severe or life-threatening situations, such as depression with psychosis or suicide risk, acute mania or schizophrenia symptoms. ECT is also administered when a person is unable to use antidepressants, or is resistant to them and also when a person refuses food or is catatonic. Muscle relaxants and anesthesia are used during ECT. Patients are closely monitored and the electric current, which is delivered in several short bursts, lasts approximately 30-60 seconds. Patients typically awaken with no memory of the procedure. While ECT therapy is generally considered safe, a number of side effects exist. Cognitive impairment, such as periods of confusion, may increase exponentially with continued treatment. Memory loss may also be an issue for some patients, either in recalling events that happened before the treatment or remembering events occurring afterward. Also, certain medical complications may occur from anesthesia. Headache, nausea, vomiting or muscle aches can all occur. ECT may be administered bilaterally to both sides of the brain. Some psychiatrists feel this causes a "better" seizure, but research argues it means more frequent memory problems. The other method for administering ECT is unilaterally, to the nondominant side of the brain. Many psychiatrists believe this is less likely to affect learning and memory functions. It's unclear how ECT works. The induced seizure may cause changes in brain chemistry that help improve symptoms in up to 80 percent of patients receiving a full course of treatment. An estimated 100,000 Americans undergo ECT therapy annually, a typical course of treatment being six to 12 sessions over approximately a month's time. Many patients report improvement during the first two weeks. ECT treatment is controversial. Opponents cite high relapse and short-lived improvements, while advocates say it's useful for drug-resistant patients. For more information on mental health issues, please see additional videos on this site.