Side Effects Of Electroconvulsive Therapy

  • Sarah Lyman Bachelor of Science (BS), Medical Biology, The University of Huddersfield
  • Jason Ha Bachelor of Medicine, Bachelor of Surgery - MBBS, University of Bristol
  • Zayan Siddiqui BSc in Chemistry with Biomedicine, KCL, MSc in Drug Discovery and Pharma Management, UCL


Electroconvulsive therapy (ECT) is a treatment prescribed to people with severe mental health problems. ECT has a long, interesting and controversial history. This year marks the 80th anniversary of a treatment of this kind being administered to a human being by Laszló Meduna in 1934.1 Although ECT has a colourful history and is still a controversial topic of debate in the present day, it is still widely used amongst health professionals, albeit under strict guidelines and careful consideration. People are reluctant to consider ECT as a treatment option due to the reputation of adverse side effects that have been associated with its use. Are these risks unfounded, or should people steer clear of the therapy, even when suffering from extreme mental health problems?

What is electroconvulsive therapy?

The general idea behind the development of ECT as a treatment arose in the early 20th century, when it was noticed during the study of the disease schizophrenia, that very few schizophrenics suffered from another neurological disorder, epilepsy. Meduna and others sought to find out whether seizures could be used as a treatment for schizophrenia. This initial hypothesis led to the development of ECT and its use over the last 80 years as a psychiatric treatment.1 

ECT induces seizures within the brain, intending to reduce and treat symptoms of other mental health and neurological disorders. The patient is anaesthetised before ECT is performed, limiting pain and discomfort during the procedure. 

When and what is ECT used to treat?

Electroconvulsive therapy as a treatment option is offered only after significant consideration. This is usually when other conventional treatment options, such as psychotherapy and medications, have failed, and the patient is exhibiting severe symptoms, which could include suicidal ideations and intense suffering. ECT will also be considered when it has proven successful in treating previous mental health episodes.2

ECT is used to treat several neurological disorders, including:

The procedure

Electroconvulsive therapy is performed by a psychiatrist alongside an anaesthetist and a nurse in a clinical setting. A full patient history will be carefully considered before the treatment can commence to ensure eligibility and limit complications. 

The apparatus

An arsenal of medical equipment is required to correctly administer the therapy as well as monitor the patient's vital signs throughout the procedure to ensure safety. The apparatus includes:

  • An ECT machine - this piece of equipment will administer the electric current to the brain via electrodes placed on the scalp.
  • An electrocardiograph (ECG) monitor - provides monitoring information of heart activity throughout the procedure.
  • An electroencephalogram monitor (EEG) - is used to monitor brain activity throughout the procedure, indicating the presence of seizure activity in the brain when ECT is administered.
  • Electromyography monitor (EMG) - measures muscular activity. During rest, muscle activity should be reduced. The EMG indicates seizure activity, as muscular activity increases during a seizure.
  • General medical equipment such as a stethoscope, pulse oximeter and blood pressure cuff will be utilised.
  • A bite block is to be placed in the mouth to prevent harm to the tongue during seizure activity.
  • Anaesthesia equipment allows the patient to be put to sleep and monitored during the procedure.
  • Muscle relaxant to ensure the patient is still during the procedure.3

Electroconvulsive therapy administration

The patient, whether being treated as an inpatient or an outpatient, will be nil by mouth for 12 hours, with fluid intake cessation two hours before therapy. 

The first stage involves the anaesthesiologist putting the patient to sleep, ensuring that no pain or discomfort is experienced during the procedure. This is followed by the administration of a muscle relaxant to limit involuntary movement that may cause injury during the procedure, as well as allowing muscular activity to be monitored effectively during the induced seizure period. A bite block will be placed in the patient's mouth to avoid injury, such as tongue lacerations during the induced seizure. The ECT machine will be set at a prescribed waveform, and the electrodes will then be placed on the scalp. The traditional electrode placement is bilateral, symmetrical placement at the left and right temples. However, treatment has evolved, and placement may be unilateral, with one designated electrode site. The ECT machine will then transmit pulses to the brain lasting for approximately 50 seconds, enough to induce a seizure in the patient. The monitoring equipment will indicate the presence of a seizure. Finally, the patient will be brought back to consciousness around 10 minutes after the therapy.

How long does treatment take?

A treatment plan will be devised by the psychiatrist in charge of the patient's care, following guidelines set out by the National Institute for Health and Care Excellence (NICE). The frequency of the ECT sessions is dependent upon the condition that is being treated and its severity. 

In the UK, it is standard practice to receive two ECT sessions per week. The treatment duration ranges from six to twelve ECT sessions. This will depend on evidence of symptom improvement and the severity of the disorder being treated. Most patients note a marked improvement after two to three sessions.4

Contraindications and people excluded from receiving ECT

Inducing seizure activity within the brain elicits physiological effects that may be unsuitable and unsafe for people with various comorbidities. The seizure activity effects include:

  • Increased intracranial pressure
  • Increased heart rate
  • Increased blood pressure

For the reasons above, some people are unable to receive ECT, including those who:

  • Suffered a recent heart attack
  • Diagnosed with heart failure
  • Taking anticoagulants (blood thinners)
  • Have an unruptured aneurysm
  • Suffered from a stroke

Other contraindications that require close monitoring, but do not necessarily exclude them from receiving treatment include:

What does it do to the brain, and why does it work?

Most people are familiar with the ghoulish portrayal of ECT and its side effects from horror stories and movies, such as the popular movie ‘One Flew Over the Cuckoo's Nest’. However, after eighty years, the treatment is still recommended, albeit more scarcely than in the 1950s and 1960s when it was a popular treatment choice for many mental health disorders, which would today be a contraindication. 

It is unclear exactly why ECT works. The induced seizure results in increased blood flow to sites of the brain affected by depression, along with a surge in neurotransmitter release, such as dopamine and serotonin. Molecular, cellular and genetic changes occur within the brain, which may also be linked to the alleviation of symptoms following treatment.6 

A recent study (2021), performed by The Royal College of Psychiatrists highlighted that of those who received ECT for treatment of severe depression, 68% noted an improvement of symptoms, with 41% entering full remission.7 It is also interesting that almost two-thirds of people receiving ECT were people assigned female at birth (AFAB), reflecting the prevalence of depression in those AFAB being twice that of those assigned male at birth (AMAB), according to national statistics.8 Furthermore, due to the advancement in treatment and the success rates highlighted above, ECT has increased in the past decade, with psychiatrists becoming more confident in offering it, and more patients keen to trial the therapy with the hope of diminishing the symptoms of their condition.7 

Side effects of ECT

The archaic depiction envisioned when ECT is brought up has led to controversy surrounding the after-effects of receiving induced seizures via ECT. Are these beliefs unfounded? To decide on this, a comprehensive review of the side effects should be conducted by both the patient and the healthcare professionals responsible for psychiatric care.

Possible side effects of receiving ECT

Some notable adverse effects may be experienced following treatment. The symptoms are usually transient and minor, with patients experiencing full recovery a short time after treatment has ceased. The side effects of receiving anaesthesia are the same as those faced when undergoing any surgery where the patient is out to sleep. 

Cognitive impairment

Memory loss is a common side effect reported by patients following ECT. Patients often report short-term memory loss, confusion, and nausea immediately following the procedure, which may last a few hours.9 In most cases, this side effect is transient, with patients regaining full cognitive function after a few hours and some taking substantially longer, with recovery taking up to six months following treatment. However, in a few patients, the effects are long-lasting.10 

People suffering from cognitive impairment may suffer from the following symptoms:

  • Inability to recognise faces and names
  • Unable to remember daily routine in the previous days
  • Forgetful and unable to focus on tasks
  • Unable to make simple decisions or perform basic problem-solving in everyday life

Memory loss is incontrovertible as the most controversial and deterring factor surrounding the negative impacts of ECT. However, the risk-to-benefit ratio sways towards the benefits associated with alleviating symptoms of severe mental health disorders, otherwise it would not be performed or recommended in modern society. It is worth noting that ECT is often a last resort in treating these conditions and is only offered where medications and other therapies have been trialled and have been unsuccessful. Furthermore, it has not been ruled out that the deficits associated with long-term cognitive impairment do not arise from the condition being treated itself. There has yet to be a conclusive, wide-participant study to confirm that ECT does cause long-term impairment in a minority of patients.10 

Headaches, nausea and muscle soreness

It is very common for patients to experience headaches and nausea following treatment. This occurs due to the dilation of blood vessels elicited by the therapy, allowing increased blood flow through the brain and temporarily raising blood pressure. The resulting symptoms generally persist for a few hours and can be treated easily with painkillers. Muscle soreness is attributed to the muscle-relaxing drugs provided during treatment, as well as the sustained contractions during induced seizure activity. These effects are again short-lasting and can be treated with painkillers.11

Cardiac complications

The mortality rates associated with ECT are recorded at approximately 3 people out of every 100,000 people.12 This statistic is no greater than that of any other minor medical procedure requiring anaesthesia. These deaths are mainly associated with cardiac complications. ECT generates a higher-than-normal workload for the heart. Stimulation of the nervous system during seizure activity dilates blood vessels, increases blood pressure, and elevates the heart rate, causing short-term stress to the heart. In healthy people, this should not cause any damage or lead to any cardiac complications. However, in people with cardiac pathologies, ECT could be particularly dangerous. Mortality is usually the result of an underlying cardiovascular condition that has not been detected during prescreening. Many cardiac problems would be a contraindication, eliminating the person's eligibility for ECT.12


The facts and statistics surrounding the use of ECT and the potential adverse side effects associated with treatment substantiate the requirement for strict eligibility criteria and limitations of its use. ECT is only considered in severe cases where other, more conventional therapies have failed. The treatment success rates are high, and the benefits to the patient are substantial. 

The side effects are taken into account during assessment against eligibility criteria, hence the reason the use of ECT is limited to people who have not improved following medication regimes and psychotherapy. These people suffer extreme symptoms that limit their quality of life and cause immense suffering. ECT is only considered in these cases, as the benefits far outweigh the risks from possible side effects. The macabre depiction of ECT in the media and from decades ago, when treatment was in its infancy, has led to a resilient attitude and unpopularity with the general public. However, mortality rates are low and in line with any other procedure performed under general anaesthetic, and the common side effects are short-lived.

In extreme cases of severe depression, for which ECT may be an option, approximately 15% of these people commit suicide. Based on this statistic, ECT has the potential to save thousands of lives that would be lost to suicide. In these cases, the benefit of ECT in saving lives outweighs the risks associated with adverse side effects.13


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  6. Singh A, Kar SK. How does electroconvulsive therapy work? : understanding the neurobiological mechanisms. Clin Psychopharmacol Neurosci [Internet]. 2017 Aug [cited 2024 Jan 18];15(3):210–21. Available from: 
  7. [Internet]. [cited 2024 Jan 18]. New data shows more than a thousand people benefit from life-saving electroconvulsive therapy, the majority of which are women. Available from: 
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  9. Macdonald W. What is Electroconvulsive Therapy (ECT)? Available from:,ineffectively%20treated%20severe%20psychiatric%20disorders
  10. Argyelan M, Lencz T, Kang S, Ali S, Masi PJ, Moyett E, et al. ECT-induced cognitive side effects are associated with hippocampal enlargement. Transl Psychiatry [Internet]. 2021 Oct 8 [cited 2024 Jan 19];11(1):1–7. Available from: 
  11. Side effects of ect | 2014 ssc2a d14 [Internet]. [cited 2024 Jan 19]. Available from: 
  12. Watts BV, Peltzman T, Shiner B. Mortality after electroconvulsive therapy. Br J Psychiatry. 2021 Nov;219(5):588–93.
  13. Kellner CH, Fink M, Knapp R, Petrides G, Husain M, Rummans T, et al. Relief of expressed suicidal intent by ect: a consortium for research in ect study. Am J Psychiatry [Internet]. 2005 May [cited 2024 Jan 19];162(5):977–82. Available from: 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Sarah Lyman

Bachelor of Science (BS), Medical Biology, The University of Huddersfield

Sarah is a Biomedical Scientist with extensive research experience in the field of Cancer Biology. She has many years experience as a College lecturer of Medical Science, an academic course leader and an expert in curriculum writing and development. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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