Electroconvulsive therapy

Electroconvulsive therapy, also known as ECT, is is the practice of inducing a seizure through the administration of an electric current through electrodes placed on the skull of an anaesthetised patient. It has previously been called electroshock therapy and in lay speech is commnly called shock therapy. The practice of electroconvulsive therapy is controversial with some quarters maligning it as babaric and backward and symbolic of psychiatry's suppression of the individual. Others view electroconvulsive therapy as having liberated from the torment of psychiatric illness.


It was first observed by Hippocrates round about 400BC that head trauma, fever and convulsions were sometimes beneficial in relieving symtoms from psychiatric illnesses. He noted that malaria-induced seizures cured some mentally insane patients. In the late 18th century the London Medical Journal published an article on the therapeutic use of seizures.

The first biological therapy for psychosis was developed in 1927 by the Polish neuropsychiatrist Sakel. He noted that psychotic symptoms improved in schizophrenia patients after they were given an overdose of insulin which induced a seizure. Insulin is normally secreted by the pancreas and allows human cells including brain cells to take up glucose. Glucose is the primary fuel of brain cells. An overdose of insulin leads to acute uptake of glucose by the body, leading to a shortage for the brain. This causes the seizures. The seizures were stopped by administration of glucose. Sakel claimed a high rate of success in treating schizophrenia patients. Studies in the US at the time observed success rated ranging from 20 to 40% with improvement in symptoms in a further significant proportion. These results were however not replicated in further more controlled studies and the popularity waned.

At about the same time in the 1930s a Hungarian physician Meduna was experimenting with the induction of seizures using various chemicals. He incorrectly concluded that epilepsy and schizophrenia were incompatable, and theorised that schizophrenia could be cured by inducing seizures. He experimented with various compounds including camphor, metrazol, strychnine, thebain and pilocarpin. He had most success with metrazol and this became the standard chemical means of seizure induction for a few years. It had some significant side effects such as seizures that were difficult to control and spinal fractures.

Bennet, a psychiatrist, then combined metrazol with a muscle relaxant, and later a sedative agent to avoid being conscious while having the seizure. Insulin shock therapy, however, was more reliable in inducing seizures, more easily stopped, had less side effects, and had more success in the treatment of schizophrenia. Due to this and to the emergence of antipsychotic medications, the use of metrazol declined.

Electroconvulsive therapy was developed in the late 1930s by the Italian Cerletti who observed the metrazol induced seizures and thought that electrically induced ones would be more reliable. He developed electroconvulsive thearpy through experiments on animals. His first therapy on a human was in 1937. An unexpected benefit was the retrograde amnesia (memory loss) that it produced for events immediately prior to the procedure, thus patients could not remember the procedure and thus were less afraid. It was also cheap, easy and quick to administer and it's use became popular.

Admittedly, electroconvulsive therapy was abused with the intention of subdueing and controlling troublesome psychiatric patients. Patients received shock treatment without sedation or muscle relaxants. Electroconvulsive therapy fell into disfavour after the deinstitutionalization of psychiatry in the 1970s. Psychiatrists also had the use of a more powerful array of antipsychotics and antidepressants.


Electroconvulsive therapy is being used more frequently today. Its use is however still stigmatised and controversial, and is still being actively campaigned against.

Electroconvulsive therapy is indicated in a few conditions. 80% of patients presenting for ECT have a diagnosis of major depression, especially with psychotic symptoms. It is also used for severe catatonic episodes and severe manic episodes. It is less frequently for schiozophrenia. ECT is used usually after the illness has not responded to medications. It is sometimes indicated in certain medical disorders such as Parkinson's disease, neuroleptic malignant syndrome and intractable seizures.

Other indications are when a quick and robust response is needed (eg post-partum period), when ECT poses less risk than medication (eg pregnancy and elderly patients), when there is a clear history of poor repsonse to medication or good response to ECT,and when the patient prefers electroconvulsive therapy to medication.


Historically the results could not be reliably interpreted because of differences in methodology that included amongst others, diagnostic over-inclusivity (including patients with other disorders), failure to use standardised rating scales, subjective definitiions of outcomes, variable patient populations, differences in the ECT technique, dosing and frequency, small patient samples, and varying use of different types and doses of antipsychotic medications.

More recent evidence has suggested that ECT is effective in combination for treatment-resistant schizophrenia, shorter duration and for relapse prevention.

World bodies give varying recommendations. The Americal Psychiatric Association (APA) states that the electroconvulsive therapy remains an important treatment modality for patients who do not repsond to medications. The World Federation of Societies for Biological Psychiatry (WFSBP), the Royal College of Psychiatrists and the National Institute for Clinical Excellence (NICE) are less positive and state that evidence for effectiveness is not conclusive and ECT is therefore not recommended routinely for this population, except if there is severe depression or catatonia.

The WFSBP have added that electroconvulsive therapy only be used in exceptional cases of refractory-schizoprenia, and the Royal College of Psychiatrists stated that ECT is 4th line option for those whom clozapine has been ineffective or intolerable.

In the last decade, there have been studies including a Cochrane review in 2005 looking at studies from 1974 to 2004, that have found the use of ECT plus antipsychotic medications to be more effective than medication alone.

Adverse effects of electroconvulsive therapy

Serious medical outcomes are rare. In a study of 8,000 patients receiving ECT over 5 years, 30 patients died within 14 days of ECT, and of these only 2 could be linked to the anaesthetic procedure required for ECT. No deaths were directly related to ECT itself.

The most important and common side effect is the effect on memory. 4 types of memory disturbance are documented.

Post ictal disorientation occurs after the seizure and is the confusion which anyone will experience after a seizure. It usually clears in a few minutes to a few hours. Some patients recover almost immediately afterwards, while others might sleep for a few hours before they recover fully.

Anterograde amnesia is the inability to learn new information after the course of ECT. This can vary in severity.

Short term retrograde amnesia involves memory loss for varying amounts of information for varying periods from weeks to months before the course of ECT. Retrograde amnesia usually improves during the first few months after the course of ECT, but recovery can be imcomplete for some patients.

Extensive retrograde memory loss is fortunately rare and invloves extensive memory loss dating back months to years.

See this link for physical side effects of ECT.

Method of ECT

ECT can be administered in various ways depending on a the amount/dose of current, the frequency of dosing, the total number of doses, the placement of the electrodes, and the typr of current administered.

These technical properties, in particular the electrical stimulus and electrode placement, can affect treatment outcomes and side effects. ECT was initially delivered using a sinusoidal waveform. Modern day machines deliver a brief pulse impulse which delivers full current strength instantaneously. This form produces a better outcome with less side effects. Most ECT centres today in the Western world will deliver a brief wave pulse form.

Electrode placement was initially bilateral over the temporal areas. In the mid 20th centuary right unilateral electrode placement was introduced to avoid the speech areas (left temporal area). Since this time it has been observed that there are less short- and long-term cognitive effects with unilateral compared to bilateral electrode placement. Electrodes have also been placed over the frontal regions but these delivered the worst outcomes and is not performed anymore.

Today high-dose, ultra-brief (wave pulse form) right unilateral ECT is regarded as being equal in efficacy to bilateral ECT, but with less cognitive side effects.

Electroconvulsive therapy is an effective and safe means of treatment for some psychiatric conditions which are life threatening and where medication has been ineffective or contra-indicated. it has proven to be most affeceive in manic and depressive disorders, but evidence is emerging of its effectiveness in treating refractory schizopohrenia patients who are also on antipsychotic medications. Challenges remain in identifying those factors associated with the more severe side effects. As with all other procedures in medicine, safety and effectiveness is determined by the team delivering it.

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