Electroconvulsive Shock Therapy Indications, History, Side Effects and More

Disclosure:  This post may contain affiliate links, meaning, at no additional cost to you, I may earn a commission if you click on, or make a purchase through a third-party link.

Electroconvulsive therapy (ECT) is a medical treatment performed under anesthesia most commonly used for patients with treatment-resistant depression and catatonia. A generalized tonic-clonic seizure is induced utilizing a small electrical current applied to the head. This seizure lasts from 30-60 seconds. 

ECT is the most rapid and effective treatment available for geriatric patients with psychosis, depression, or bipolar disorder, according to research studies.1

Many believe ECT to be the most effective treatment for depression for all patients. 

This procedure has been a topic of controversy ever since Ken Kesey released “One Flew Over the Cuckoo’s Nest” in 1962. This book was made into a movie in 1975 starring Jack Nicholson and depicted ECT and lobotomies as a method of torture utilized in psychiatric hospitals. This did not sit well with the counterculture movement.

ECT is one of the safest procedures performed under general anesthesia, with only two to four deaths per 100,000 treatments. This is likely because ECT is a short procedure.

History of ECT

The first convulsive therapy was performed in Budapest in 1934 using pentylenetetrazole (Metrazol). Metrazol was used as a circulatory and respiratory stimulant but caused seizures in high doses. It was useful for depression as a convulsant, but side effects and uncontrolled seizures limited its use. 2

Ladislas Meduna gave an IM dose of camphor to a patient who had been in a catatonic stupor for four years in 1934. It is reported that two days after his fifth injection on February 10, 1934, the patient got out of bed, requested breakfast, got dressed, and began to talk. 3

A psychiatry professor, Dr. Ugo Cerletti, induced convulsions by applying electricity directly to the brain at the University of Rome in 1938. Dr. Cerletti achieved success with this method in patients with schizophrenia. 4

In 1938, Cerelli gave the first public presentation on ECT at the Medical Academy of Rome. By 1943, ECT was being used in America. Initially, it was used for schizophrenia, but over time ECT was utilized to treat most psychiatric disorders. After several years, ECT became a common treatment for depression with psychotic features as well as severe mania.

Antidepressants first began to appear in 1958 when an anti-tuberculosis drug, iproniazid (Marsilid), started to be used off-label for depression. This drug was eventually removed from the market due to safety concerns.

 In 1959 imipramine (Tofranil) was approved by the FDA for major depressive disorder (MDD). This was the first tricyclic antidepressant (TCA).

Although the psychiatric community had high hopes following the invention of the TCA’s, these drugs were not 100% effective, and they were associated with side effects. The use of ECT decreased by 46% between 1975-1980, but ECT began to increase in popularity during the 1980s. In the United States in 1980, 2.4% of all hospitalized psychiatric patients received ECT treatment. 5

ECT Safety

As discussed in the introduction, ECT is a safe procedure. Recent studies have suggested depression is associated with a loss of gray and white matter in different parts of the brain. This neurodegeneration is more prevalent in patients with a more extended history of depression, untreated depression, and a larger number of depressive episodes. This suggests rapid treatment of depression as achieved with ECT can reduce the risk of neuropathologic changes. 6

Postmortem studies of ECT patients who had the procedure done with modern techniques do not show brain damage resulting from the ECT itself. 7

ECT for Behavioral and Psychological Symptoms of Dementia (BPSD)

BPSD is a reality for most dementia patients and their families. This is a common reason for hospital admissions. Symptoms of BPSD include agitation, aggression, disinhibition, apathy, depression, sleep and appetite changes. 

There are no medications approved for dementia besides the anticholinesterase inhibitors and memantine. These drugs slow the progression of dementia but usually have little effect on BPSD. We use antipsychotics to treat these behaviors. Antipsychotic agents all have significant side effects associated with them and an FDA boxed warning for increased mortality risk in elderly patients.

A retrospective chart review of sixty elderly dementia patients with BPSD receiving ECT for agitation was published on September 23, 2019. They found ECT to be safe in their population and very effective in reducing agitation and decreasing the psychotropic pill burden as well. There are other hurdles one must consider when utilizing ECT for dementia patients. The largest is that of consent. Most dementia patients are not able to agree with an ECT procedure.


ECT for Catatonia

Catatonia is a condition in which the patient has a significant decrease in their reaction to the environment. Catatonic patients are often mute, appear to be in a stupor, and may demonstrate negativism or motor rigidity. 

The initial treatment for catatonia is benzodiazepines. Many catatonic patients initially respond to IV lorazepam. The conversion to oral lorazepam dosing can sometimes lead to rebound catatonia in which the IV form may need to be reintroduced, or the oral dose increased. 

If the patient does not respond to a benzodiazepine in 2 to 3 days, or if the symptoms are particularly malicious, ECT is the best treatment option. Electroconvulsive therapy works synergistically with benzodiazepines and is beneficial in up to 80% of patients. 8

ECT in Clozapine-Resistant Schizophrenia (CRS)

Clozapine remains the drug of choice for treatment-resistant schizophrenia. Because schizophrenia is a chronic debilitating disease, it is crucial to find effective treatment methods. Clozapine is superior to other antipsychotics with regards to improved social functioning, symptom improvement, and reduction of hospitalization and mortality. Unfortunately, clozapine does not work for every patient. In 2018, Wang et al. evaluated the safety and efficacy of using ECT in addition to clozapine in the treatment of CRS. This meta-analysis showed adding ECT to clozapine was superior to monotherapy. The main adverse effects suffered in these trials were memory impairment (24.2%) and headache (14.5%). These side effects were mostly mild and short-lived. 9

ECT VS. Antidepressant Medications

The FDA performed a systematic review and Meta-Analysis of randomized, controlled trials examining the effectiveness of ECT in 2011. They came to the following conclusions with regard to ECT and antidepressant medication.

  • Immediately to one-month post-ECT, there is conflicting evidence that ECT is more effective than antidepressant medications.
  • One-month post-ECT, conclusive evidence shows ECT to be more effective than antidepressant medication. 


ECT Delirium

There have been cases of delirium reported after ECT treatments. After medical causes are ruled out, delirium may be effectively managed by changing to unilateral ultra-brief pulse ECT with a greater interval between treatment sessions. 10

Lithium is one of our best treatments for bipolar disorder. It is often used for treatment-resistant major depressive disorder (MDD.) There are times when it is beneficial to use Lithium and ECT together as the combination of the two seems to be more effective than either treatment alone. A study published in August of 2019 found that patients treated with lithium and ECT during an inpatient stay had an 11.7 fold higher risk of delirium than those being treated with ECT alone. 11

Lithium should only be used in conjunction with ECT for severe cases or when the risk of suicide is high to prevent delirium.

ECT and Cognitive Function in Major Depression

A paper published in the Journal of Affective Disorders in 2019, discussed a prospective study following twenty-seven depressed patients before, and two years after ECT. The purpose was to measure remission rates as well as any cognitive changes that may be caused by ECT treatment. 

They found improved neurocognitive function two years after ECT regardless of remission status. The remission rate reached 62.9% at two years. The relapse rate was low; 22% relapsed before the six-week follow-up, and 7.4% between six months and two years after ECT. 12

Although the ECT methods were not uniform in this study, and the sample size was small, the results suggest ECT is beneficial in the treatment of depression without negatively affecting cognitive function.

ECT and Age

A study was done to compare various aspects of ECT on three different age groups:

Young (18-45 years)

Middle (46-64 years)

Old (>=65 years)

A total of 402 patients were evaluated the day before ECT and one-week after. 

One week after ECT, the middle and old age groups showed a significant improvement in the Mini-Mental State Examination (MMSE) score when compared to baseline. Rates of response were not statistically different in the three groups. There was also no difference in premature drop-out rates.

This study concluded ECT was a viable treatment for elderly patients with treatment-resistant depression. Rates of response were near 70%, and no life-threatening adverse events occurred. 13

ECT Contraindications


  • Elevated intracranial pressure.
  • Recent myocardial infarction.
  • Heart Failure.
  • Severe Hypertension.
  • Pheochromocytoma.
  • Risk of bleeding.
  • Unruptured aneurysm.
  • Recent stroke.

Side Effects of ECT

  • Memory loss
  • Confusion
  • Nausea
  • Headache
  • Muscle Pain
  • Complications from Anesthesia
Michael Brown pictured with Final Thought written

Electroconvulsive therapy can be a life-changing procedure for many patients. For those who do not experience relief from antidepressant medications, ECT can be their last hope. It is also useful in treatment-resistant catatonia, dementia with BPSD, and clozapine-resistant schizophrenia. 

This procedure has undergone many improvements over the years. No longer do patients have to worry about broken bones caused by seizures. Today, psychiatrists utilize neuromuscular blocking agents which confine seizure activity to the brain. 

The studies support the use of ECT. I have personally viewed several treatments during my Pharmacy Directorship at a private psychiatric hospital in the late 1990s. The procedure is quick, mild, and most adverse reactions are the result of anesthesia. More importantly, ECT is an effective treatment for a vulnerable segment of our population.

As a society, it is our responsibility to take care of our mentally ill population. We should not have these patients living in tents on the side of the road in our major cities. Psychiatric patients are people like us who have a brain disorder. Remember, this can happen to anyone. Electroconvulsive therapy is not a punishment for bad behavior. It is an effective treatment for several debilitating conditions that are resistant to other, less invasive therapies.

If you have any questions or concerns, feel free to contact me. I will answer every message received.

Always strive to live a happy, healthy life.

Michael Brown in Lab Coat with arms crossed

Michael J. Brown, RPh, BCPS, BCPP

Mr. Brown is a Clinical Pharmacist specializing in pharmacotherapy and psychiatry.

Read Michael’s story here.

Feel free to send Michael a message using this link.