Some 100,000 Americans undergo electroconvulsive therapy (ECT) treatments for depression each year. Deciding whether ECT is a good treatment option for you or a loved one can be a difficult decision. But it is an option worth exploring when depression is severe. In this Health Alert, Johns Hopkins provides a primer on ECT.
Modern-day ECT is a far cry from the decades-old methods that earned ECT its sinister reputation. The treatment has evolved into a relatively painless procedure with proven effectiveness in the fight against depression. It has survived its critics because it is safe when administered by experienced doctors and nurses and because it works.
ECT involves passing a carefully controlled electrical current through a person's brain to trigger a seizure -- a rapid discharge of nerve impulses throughout the brain. The electricity is passed between two electrodes that are placed on the patient's scalp. When the current is passed between the electrodes, a generalized seizure that typically lasts for 30–60 seconds is produced in the brain.
Exactly how the seizure alleviates depression remains a mystery to neuroscientists and psychiatrists. Depression is believed to be caused, at least in part, by an imbalance in the brain's chemical messenger system. ECT somehow works to rebalance that system. Many rodent studies have been conducted in hopes of better understanding ECT's mechanism of action, but they have not been informative in any definitive way.
What scientists do know is that, despite the increase in brain activity caused by the induced seizure, there is a net decrease in activity in certain areas of the brain following ECT. One hypothesis is that, by inducing a seizure -- the absolute strongest stimulus the brain can take -- there is a consequent dampening down of brain circuits afterward. This quieting of the brain, it is thought, may help alleviate symptoms of depression.
Doctors who perform ECT essentially treat people with depression who are medication resistant or who have suboptimal responses to the medicines, and about 85% of these difficult-to-treat patients improve with ECT. This is a remarkably high response rate in a severely depressed group of people.
