Electric Shock Therapy (ECT): How It Works and What Studies Show

Electric shock therapy is the common name for electroconvulsive therapy (ECT), a procedure that uses an electric current to induce brief seizure activity in the brain to treat serious mental disorders^[7]. It has the longest history of use for depression of any brain stimulation therapy^[7].

The FDA clears ECT devices for catatonia and for severe depressive episodes in major depressive disorder or bipolar disorder, in patients age 13 and older who are treatment-resistant or need a rapid response^[8]. How often depression fails to respond to standard care is covered on the treatment-resistant depression page.

Modern ECT is given under general anesthesia. Patients receive a short-acting anesthetic and an intravenous muscle relaxant first, so the body stays still and the patient does not feel the electrical pulses^[7].

Shock therapy, electroshock therapy and electro shock therapy all describe the same procedure; clinicians and researchers call it ECT or ECT therapy. Muscle stimulators and TENS units sold for back pain are different devices that are not designed to cause seizures.

Electrodes are placed at set points on the head, and a current passes through them to cause seizure activity that lasts under a minute^[7]. A blood pressure cuff on one arm or leg often blocks the muscle relaxant in that limb, so the team can watch it move and confirm the seizure was adequate^[7].

Heart rate, blood pressure and breathing are monitored throughout, and the anesthesia risk is similar to that of other minor procedures, according to the University of North Carolina's ECT service^[9]. ECT can be scheduled for inpatients or outpatients^[9].

How often and how many treatments

A typical course runs three times a week until symptoms improve, usually within 6 to 12 treatments^[7]. UNC describes an initial series of two or three treatments a week lasting roughly 3 to 5 weeks^[9]. Many patients also take an antidepressant or mood stabilizer during the course^[7].

Electrode placement and pulse width

Two settings shape the balance between benefit and memory effects. Bilateral ECT, with electrodes on both sides of the head, causes more memory problems than right unilateral ECT, which places one electrode on the right side and the other on top of the head^[7].

NIMH describes brief and ultra-brief pulses as effective as the traditional form at a lower dose, with fewer cognitive side effects^[7]. A 2020 clinical review is more cautious: efficacy rises from ultra-brief unilateral to standard unilateral to bilateral ECT, and cognitive side effects rise along the same gradient^[6].

How people feel after a treatment

Patients wake 5 to 10 minutes after the procedure, often groggy, and are usually alert after about an hour^[7]. The most common side effects are headache, upset stomach, muscle aches, disorientation and memory loss^[7].

Because anesthesia and confusion can linger, UNC requires patients to arrange transportation and not drive until the next day after ECT^[9].

ECT is usually considered only after psychotherapy or medication has not helped^[7]. NIMH lists two qualifying situations: severe treatment-resistant depression, or a need for rapid response because of life-threatening circumstances such as catatonia, suicidality or malnutrition^[7].

It is also used when medications cannot be tolerated or are undesirable because of physical illness, which NIMH notes is often the case in older adults^[7]. In some cases ECT has been used for schizophrenia, schizoaffective disorder and mania^[7].

In U.S. general hospitals, depressive disorders were the most common primary diagnosis for stays involving ECT in 2019 and 2020, followed by bipolar and related disorders, schizophrenia spectrum disorders and neurocognitive disorders^[1].

State law can be stricter than the FDA's age-13 floor^[8]. Texas prohibits ECT for anyone younger than 16^[10].

For severe depression, the short-term evidence is strong. A 2003 Lancet meta-analysis by the UK ECT Review Group found real ECT significantly more effective than simulated ECT (6 trials, 256 patients) and more effective than drug therapy (18 trials, 1,144 participants)^[2].

The authors concluded that ECT is an effective short-term treatment for depression and probably more effective than drug therapy, that bilateral ECT is moderately more effective than unilateral ECT, and that high-dose ECT outperforms low-dose^[2]. ECT also works quickly, usually taking effect within the first week of treatment^[7].

ECT versus ketamine

The largest head-to-head trial, ELEKT-D, randomized 403 patients with treatment-resistant major depression without psychosis to ECT three times a week or intravenous ketamine twice a week for 3 weeks^[3]. Response rates were 41.2% with ECT and 55.4% with ketamine, and ketamine met the trial's test for noninferiority^[3].

The trial was open-label and excluded psychotic depression^[3]. Its 3-week treatment phase is also shorter than the 3-to-5-week series UNC describes^[9], so the result does not settle the comparison for every patient.

Mortality and suicide associations

A 2025 meta-analysis of 17 studies covering 1,182,501 people found ECT associated with lower all-cause mortality (hazard ratio 0.70)^[11]. ECT was associated with lower suicide risk at 3 months of follow-up (hazard ratio 0.53) but not at 1, 6 or 12 months^[11].

The authors described any suicide protection as transient and inconsistent^[11]. These are observational associations, not proof that ECT caused the difference. Data on suicidal ideation are on the condition page.

The FDA's 2018 order lists cognitive and memory impairment and death as the identified risks of ECT devices^[8]. In the additional voluntary adverse-event reports the FDA reviewed for that order, cognitive changes were the most commonly cited problem, notably memory loss in 52 percent of reports^[8].

Short-term memory and learning

The ability to learn new information drops during and just after a course. Meta-analyses summarized in a 2020 BJPsych Open review show it returning to baseline between 4 and 14 days after the course ends, with no objectively measured impairment beyond 14 days^[6].

In the ELEKT-D trial, ECT patients showed a larger drop in delayed recall after 3 weeks than ketamine patients (T-score change of −9.7 vs. −0.9), followed by gradual recovery during follow-up^[3].

Loss of personal memories

The more lasting effect is retrograde amnesia, meaning gaps in autobiographical memory. It is usually worst for the 3 months before ECT, sometimes extends back up to 1 year, and persisted in studies that measured it for at least a year^[6].

Women and people receiving bilateral ECT appear more at risk, and higher electrical doses increase the effect^[6]. Patients' own reports of memory problems correlate poorly with objective tests, which complicates research on the question^[6].

Heart events and death

A 2019 meta-analysis of 82 studies, 106,569 patients and 786,995 treatments found that major cardiac events and death occur in about 1 in 50 patients^[5]. All-cause mortality was 0.42 deaths per 1,000 patients and 0.06 deaths per 1,000 treatments^[5].

The most commonly reported cardiac events were acute heart failure, arrhythmia and acute pulmonary edema^[5].

A course of ECT treats an episode but does not, on its own, prevent the next one. In a 2013 meta-analysis of 32 studies, 37.7% of patients on continuation medication relapsed within 6 months of successful ECT, and 51.1% within 12 months^[4].

Continuation ECT had a similar 6-month relapse rate of 37.2%^[4]. Without active treatment the rate was higher: in modern placebo-controlled trials, 78.0% relapsed within 6 months^[4].

That is why NIMH describes follow-up treatment with antidepressants, maintenance ECT or both as usually required^[7]. Maintenance ECT can range from one session a week to one every few months^[7].

Yes. In 2019, 14,230 U.S. inpatient hospitalizations involved ECT, with 52,450 inpatient procedures in total^[1]. In 2020, the first year of the COVID-19 pandemic, hospitalizations with ECT fell to 12,055 and procedures fell 10.0% to 47,180^[1].

Use had already been falling. Between 1993 and 2009, annual general-hospital stays involving ECT fell from 12.6 to 7.2 per 100,000 U.S. adults, and the share of general hospitals offering it fell from 14.8% to 10.6%^[12].

When ECT started, and whether it was banned

Ugo Cerletti and Lucio Bini first applied ECT to a patient in Rome in April 1938, after Meduna had induced seizures with camphor injections in 1934^[13]. The muscle relaxant curare was first used to soften ECT convulsions in 1940^[13].

ECT is the only one of that era's four somatic therapies still in use^[13]. The history of another, psychosurgery, is covered in What Does Lobotomized Mean?

ECT has never been banned in the United States. In December 2018, the FDA moved ECT devices for severe depressive episodes and catatonia from class III to class II (special controls) and required premarket approval for all other uses^[8].

States can add limits. Texas prohibits ECT for anyone under 16 and requires facilities and physicians who give it to file quarterly reports covering patient counts, reported memory losses and fractures, and autopsy findings when a death follows within 14 days^[10].