Multiple clinical trials have shown ECT to be effective for depression. In the Consortium for Research in ECT (CORE) study of nearly 400 people, 86 percent of people who had ECT saw their depression go away. This is significantly higher than the 21 to 30 percent remission rate with a single medication trial.

Despite its effectiveness, treatment with ECT is far from trivial. Like any epileptic activity, ECT can interfere with memory. It's common to have trouble learning new information in the weeks after ECT treatments, although this effect is temporary. Some people also forget events that occurred immediately before the sessions.

Even more disturbing is the small percentage of people who complain of persistent memory problems—a phenomenon for which few data exist. Many people who have ECT are older and already experiencing memory loss, so it's difficult to know whether the treatment is at fault. In fact, ECT often improves memory because depression itself often impairs cognitive function.

Reducing the side effects of ECT

Doctors have been working to refine ECT in an effort to minimize side effects such as confusion and memory loss. Two of these refinements are unilateral ECT and the use of ultra-brief pulses.

At Johns Hopkins, doctors generally use unilateral ECT instead of bilateral ECT. In unilateral ECT, one electrode is placed at the top of the head and the other is placed on the right temple so the current passes through only the right side of the brain. In bilateral ECT, one electrode is placed on the left side of the head and the other is placed on the right side so the current passes through both sides of the brain.

Hopkins also regularly employs narrower electrical pulses known as ultra-brief pulses, especially for people receiving ECT as outpatients. These narrower pulses last less than half a millisecond, whereas traditional pulses last for 1 millisecond. Researchers have found that ultra-brief pulses work well and are associated with less memory loss than traditional pulses, although it may take patients a few more treatments to recover than with treatment using traditional pulses.

Keeping depression at bay

An important shortcoming of ECT is that its effects often wear off after just a few weeks. Most people take antidepressants after ECT to keep depression at bay, an approach that tends to work even in those whose depression didn't respond to drugs initially.

People who aren't able to take medication—or whose depression comes back despite antidepressant treatment—have the option of maintenance ECT. This may involve a treatment every two to four weeks.

Other potential treatments for depression that doesn't respond to drugs or talk therapy include transcranial magnetic stimulation, vagus nerve stimulation and light therapy. None of these appear to be nearly as effective as ECT, however.

A lifesaving treatment

Although ECT is considered relatively safe, an estimated 1 in 10,000 patients die due to the procedure. This rate is about the same as that associated with minor surgery with similar anesthesia. There is also a theoretical risk of heart problems and injuries such as broken bones, although modern techniques and careful monitoring have made these highly unlikely.

Those who treat depression emphasize that it's important to put the risks of ECT in context. Although far from perfect, ECT is sometimes the only thing that works to relieve the intense suffering of depression. Because as many as 15 percent of people with depression die due to the disorder, mainly by suicide, ECT can be a lifesaver. For people with severe depression, who are often completely unable to function in their daily activities—unable to eat or take care of themselves—ECT can lead to remarkable recoveries.

Publication Review By: Karen L. Swartz, M.D.

Published: 21 Aug 2013

Last Modified: 21 Aug 2013