Treating Depression With Electroconvulsive Therapy

By Sarah Hollingsworth Lisanby, MD Professor and Chair, Department of Psychiatry and Behavioral Sciences Director, Brain Stimulation and Neurophysiology Center Duke University School of Medicine

Posted on | By Sarah Hollingsworth Lisanby, MD

Electroconvulsive therapy (ECT) refers to the most effective and rapidly acting treatment that we have today for severe depression and other conditions. ECT is an approved medical treatment that involves the use of electricity to produce a brief seizure in a person under general anesthesia (while the person receiving the treatment is asleep). The seizure usually lasts about a minute or less and body movement (convulsion) is very little because of a strong muscle relaxant medication which is given following the anesthetic drug. ECT is given 2-3 times per week, usually for 6 to 12 treatments. ECT is performed by medical physicians (a psychiatrist and an anesthesiologist), assisted by nurses and other medical staff.

ECT is recommended when a severe clinical depression is not responding to other treatments (such as psychotherapy and medications), or when there is a need for a rapid response (such as when there is a high risk of suicide, or the when the depression itself is threatening the health of the person). As such, ECT can be a lifesaving treatment because it is rapidly effective, even when other treatments fail. Even though ECT has been around for many years, modern ECT bears little resemblance to its historical portrayal and has been modernized.

What are the benefits of ECT?

ECT results in rapid resolution of the symptoms of major depression (including depressed mood, lack of interest, appetite and weight disturbance, sleep disturbance, feelings of hopelessness and helplessness, loss of self esteem, and thoughts of suicide). Remission, which is the likelihood of having complete resolution of symptoms, is reported to range from 70-90% with ECT. It is much more effective than any medication we have at present, which typically have remission rates around 20-30%.

ECT is also effective in the manic phase of bipolar disorder. Response is particularly high for depressed people who are psychotic or catatonic. ECT can also be used in other conditions when other treatments are not sufficiently effective, such as schizophrenia, Parkinson’s disease, and treatment-resistant epilepsy (including status epilepticus, which is a life-threatening condition).

How does ECT work?

The “active ingredient” of ECT is the seizure. There are many theories about how seizures works in depression. Seizures result in many measureable changes in brain function and chemistry. We can see these changes using special types of brain scans and other types of medical testing.

ECT has an immediate effect on the brain’s major neurotransmitters (the chemicals used by brain cells). A series of ECT treatments causes changes in functional networks that are implicated in depression, and results in neurochemical changes, some of which are also seen, to a lesser degree, with medications. Which of these changes are key to the antidepressant efficacy of ECT is a topic of active research. As ECT is the most effective treatment we have today for depression, answering the question of how it works is a top priority for our field.  Unlocking the mystery as to how ECT works when all else fails for severe depression may point the way to the development of more effective treatments in the future. 

How do you know when ECT is the right treatment?

ECT is indicated for severe clinical depression or bipolar disorder, and other conditions. ECT is typically used when depression is very severe, or has lasted for a long time and not gotten better with psychotherapy and medications. Sometimes a change in medication dosage, or a switch in medication will be effective for depression, but when it is not, there may be a role for ECT. As stated earlier, certain types of depression (such as psychotic depression) or catatonic symptoms predict better response to ECT. There is some evidence that older people actually respond better to ECT than those who are younger.

What are the risks of ECT?

Nearly all medical procedures have a risk of side effects. In the case of ECT, the risks relate to the anesthesia, and to the seizure. The risks of anesthesia are relatively low because ECT involves a very brief period of anesthesia, typically lasting less than 10 minutes. Before undergoing ECT, people are evaluated by the anesthesiologist to identify any special risks that anesthesia may pose for them. Unless the person has a very serious medical illness, the risk of life-threatening side effects is extremely rare.

The common risks of the seizure include difficulty with memory (amnesia), as well as temporary headache or muscle aching. The types of memories that can be affected include memories of the past (retrograde amnesia), and the ability to remember new information (anterograde amnesia). Many patients experience some degree of anterograde amnesia, but this typically disappears soon after the ECT course ends. People receiving ECT can experience varying amounts of retrograde amnesia. Retrograde amnesia typically deals with events that occurred close in time to the ECT, but it can extend further into the past. The amount of memory effect depends to a large extent on the type of ECT received. Right unilateral ECT (where the right side of the head is stimulated) has less risk of memory loss than bilateral ECT (where the both sides of the head are stimulated). Ultrabrief pulse ECT (which uses a very small amount of electricity) has less risk of memory loss than earlier types of ECT treatment. 

Does ECT damage the brain?

No. Careful studies using sensitive brain imaging measures in people receiving ECT, and precise anatomical measurements in animal research studies, have repeatedly demonstrated that ECT does not damage the brain.

How has ECT been modernized over the years?

Medical advances have dramatically modernized ECT, improving its safety. These advances include general anesthesia, the switch to safer types of electrical stimulation (such as the ultra-brief pulse stimulus and the ability to customize the stimulus dose to each person receiving ECT), and the use of right unilateral electrode placement. Each of these advances has substantially improved the safety of ECT. 

What about brain stimulation without inducing a seizure?
There are a number of ways to stimulate the brain with electrical and magnetic fields without causing a seizure. The only one of these procedures that is currently FDA approved for clinical depression is transcranial magnetic stimulation (TMS).

TMS uses magnetic fields to produce small electrical currents in specific areas of the brain for the treatment of depression. TMS may be indicated when a person fails to respond to one (but not more than one) adequately dosed antidepressant medication in the present episode of depression. In contrast, ECT is effective even after multiple medications have failed to improve depression. TMS is more commonly used for less severe cases of depression, while ECT remains an effective treatment for severe, medication-resistant depression. 

What does the future hold?

ECT has been modernized greatly over the years, with each advance leading to improvements in safety. Research is continuing to come up with even newer means to improve the safety of seizure therapy. One such experimental advance developed by our team is the use of magnetic fields to induce the seizure more safety. This is called Magnetic Seizure Therapy (MST). Magnetic fields are more controlled, and can target specific brain regions more accurately than standard ECT.

MST is an experimental treatment that combines the advantages of magnetic fields with the efficacy of seizures, in an attempt to lower the risk of memory loss. Results to date have been encouraging, and studies are underway comparing standard ECT with MST. We are also conducting research into ways to prolong the beneficial effects of ECT and prevent relapse, with a special focus on depression in the elderly. Depression can come back in the weeks to months following ECT, so it is important to receive a maintenance treatment to sustain the benefits.

We are currently researching the best way to maintain remission following ECT by comparing medications with continuing single ECT treatments on a maintenance schedule based upon individual symptoms, so a person only receives a treatment when they need it.

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