Electroconvulsive therapy

Electroconvulsive therapy, also known as electroshock or ECT, is a controversial type of psychiatric shock therapy involving the induction of an artificial seizure in a patient by passing electricity through the brain. Researchers remain uncertain as to exactly how ECT affects improvements in mental state, though patients with a variety of conditions have shown improvement after the procedure. Large segments of the public came to view ECT in a negative light after several unfavorable depictions in popular books and films.

ECT was first introduced as a treatment for schizophrenia in the 1930s, and quickly became adopted as a common treatment method for mood disorders—and as a dreaded mechanism for disciplining unruly psychiatric inpatients. While its use today has mostly been displaced by medication, ECT (now administered under anaesthesia and muscle relaxants) continues to be used for the treatment of several conditions for which medication is not appropriate, occupying a narrow but important niche in modern psychiatry.


Current usage

Currently ECT is mainly used to treat severe depression, particularly if complicated by psychosis (NIH & NIMH Consensus Conference, 1985; Depression Guideline Panel, 1993; Potter & Rudorfer, 1993). It is also used in cases of severe depression where antidepressant medication (sometimes in multiple courses), psychotherapy, or both have proven ineffective (Potter et al., 1991; Depression Guideline Panel, 1993), when medication cannot be taken, or when other treatments would be too slow (for example, in a person with delusional depression and intense, unremitting suicidality). Specific indications include depression accompanied by a physical illness or pregnancy, which renders the use of the usually preferred antidepressants dangerous to the patient or to a developing fetus. Under such circumstances, carefully weighing risks and benefits, some psychiatrists consider ECT to be the safest treatment option for severe depression. It is also sometimes used to treat the manic phase of bipolar disorder and in the uncommon condition of catatonia.

ECT should be administered under controlled conditions, with appropriate personnel (Rudorfer et al., 1997) and some mental health laws mandate this.

Recent epidemiological surveys in the United States show that the modern use of ECT is generally limited to evidence-based indications (Hermann et al., 1999). Indeed, concern has been raised that in some settings, particularly in the public sector and outside major metropolitan areas, ECT may be underutilized due to the wide variability in the availability of this treatment across the country (Hermann et al., 1995). Consequently, minority patients tend to be underrepresented among those receiving ECT (Rudorfer et al., 1997).


The aim of ECT is to induce a bilateral grand mal seizure (with contractions and twitching of both sides of the body) which lasts at least 20 seconds.

Before the discovery of muscle relaxants ECT was given unmodified. The patients were rendered instantly unconscious by the electrical current but the strength of the muscle contractions from the electricity and the subsequent fit at times led to complications such as compression fractures of the spine or damage to the teeth. Muscle relaxants allow a modified fit where the strength of the contractions is minor or even nonexistent. However, the use of muscle relaxants requires that the patient is first given a general anaesthesia to prevent the patient from experiencing the very uncomfortable state of being paralysed. The end result though is that the patient drifts off to sleep with the anaesthesia and wakes up a short time later being unaware of details of the procedure.

To induce the seizure, short bursts of a fixed current (typically 0.9 A) are passed through electrodes applied to the scalp at specific points using a gel, paste or saline solution to prevent burns to the skin. Modern ECT machines regulate the current to keep it constant and thus the voltage may vary up to a maximum, typically 450 V, but is usually around half that level in most cases. Modern machines are usually set in joules. The ECT therapist tries to keep the total energy as low as possible by restricting the strength and duration of the shock. The existence of the seizure is confirmed by observation or by EEG monitoring (http://www.psychiatrictimes.com/p980570.html).

Electrical current flows between two electrodes placed on the scalp, usually from temple to temple in the past, though these days ECT is more commonly applied to the non dominant hemisphere of the brain. Placement of both stimulus electrodes on one side of the head ("unilateral" ECT), over the nondominant (generally right) cerebral hemisphere, results in delivery of the initial electrical stimulation away from the primary learning and memory centers. If unmodified, the resultant seizure is characteristically more severe than a naturally occurring epileptic seizure. The production of an adequate, generalized seizure using the proper amount of electrical stimulation is required for therapeutic efficacy (Sackheim et al., 1993).

Following the seizure, there is a short period of time during which cortical electrical activity in the brain ceases and an EEG reading is flat. Opponents of the practice claim that this is no different from the state of being brain dead, and that brain cell death occurs during this time, although there is little or no empirical evidence to support the latter claim. After treatment, patients have no memory of the seizure or events immediately preceding it. Some medical professionals have made the analogy that this brief state is similar to a computer resetting itself - that it would be this reset that gives ECT a therapeutic effect.

Therapeutic ECT is usually administered as a course of 6 to 12 treatments, administered at a rate of three times per week, on either an inpatient or outpatient basis. Studies have shown that each fit must be separated by a day at least.

The exact mechanisms by which ECT exerts its therapeutic effect are not known, but studies show that repeated applications have effects on several kinds of neurotransmitters in the central nervous system. ECT seems to sensitize two subtypes of serotonin (5-HT) receptor, thereby strengthening signaling. ECT also decreases the functioning of norepinephrine and dopamine inhibiting auto-receptors in the locus coeruleus and substantia nigra, respectively, causing more of each to be released (Ishihara K, Sasa M., 1999).

Risk, side effects and complications

The major risks of ECT are those of brief general anesthesia. There are virtually no absolute health contraindications precluding its use where warranted (Potter & Rudorfer, 1993; Rudorfer et al., 1997).

The most common adverse effects are confusion and memory loss for events surrounding the period of ECT treatment. The confusion and disorientation seen upon awakening after ECT typically clear within an hour.

More persistent memory problems are variable. Most typical with standard, bilateral electrode placement (one electrode on each side of the head) has been a pattern of loss of memories for the time of the ECT series and extending back an average of 6 months, combined with impairment with learning new information, which continues for perhaps 2 months following ECT (NIH & NIMH Consensus Conference, 1985). Some neuropsychological studies have shown that by several months after completion of ECT, the ability to learn and remember are normal (Calev, 1994). Although most patients return to full functioning following successful ECT, the degree of post-treatment memory impairment and resulting impact on functioning are highly variable across individuals (NIH & NIMH Consensus Conference, 1985; CMHS, 1998). While clearly the exception rather than the rule, a number of rather vocal former psychiatric patients opposed to ECT anecdotally claim that their memories were permanently and severely damaged by the procedure. No reliable data on the incidence of severe post-ECT memory impairment are available.

Fears that ECT causes gross structural brain pathology have not been supported by decades of research in both humans and animals (NIH & NIMH Consensus Conference, 1985; Devanand et al., 1994; Weiner & Krystal, 1994; Greenberg, 1997; CMHS, 1998). Recent studies suggest the opposite; long term ECT treatment, like antidepressant treatment, seems to protect the brain from the damaging effects of depression. ECT increases the expression of brain-derived neurotrophic factor (BDNF) in the limbic system, stimulating growth and protecting neurons from the atrophy that long term depression can otherwise cause (Duman RS, Vaidya VA., 1998). Still, the decision to use ECT must be evaluated for each individual, weighing the potential benefits and known risks of all available and appropriate treatments in the context of informed consent (NIH & NIMH Consensus Conference, 1985).

After the course of ECT ends, memory gradually improves, though whether it ever returns to pre-ECT levels is highly variable. Some patients anecdotally claim their memory is permanently impaired following ECT, while a few even report better memory afterwards.

The muscle relaxants can produce generalised but mild aches in the muscles after waking.

Unilateral ECT

Two forms of ECT exist: bilateral and unilateral. In bilateral ECT, the current is passed across the temporal lobes, with an electrode being placed on either side of the head. With unilateral ECT, the electrodes are only placed on the right side of the head, to pass the current primarily through the right temporal lobe.

According to several controlled trials, unilateral ECT is associated with virtually no detectable, persistent memory loss (Horne et al., 1985; NIH Consensus Conference, 1985; Rudorfer et al., 1997). However, most clinicians find unilateral ECT less potent and more slowly acting an intervention than conventional bilateral ECT, particularly in the most severe cases of depression or mania. One approach that is sometimes used is to begin a trial of ECT with unilateral electrode placement and switch to bilateral treatment after about six treatments if there has been no response.

Research has demonstrated that the relationship of electrical dose to clinical response differs depending on electrode placement; for bilateral ECT, as long as an adequate seizure is obtained, any additional dosage will merely add to the cognitive toxicity, whereas for unilateral electrode placement, a therapeutic effect will not be achieved unless the electrical stimulus is more than minimally above the seizure threshold (Sackeim et al., 1993).

Even a moderately high electrical dosage in unilateral ECT still has fewer cognitive adverse effects than bilateral ECT. On the other hand, high-dose bilateral ECT may be unnecessarily risky and may be a preventable cause of severe memory impairment.

Use in combination with medications

Some types of medication, such as lithium, also add to confusion and cognitive impairment when given during a course of ECT and are best avoided. Medications that raise the seizure threshold and make it harder to obtain a therapeutic effect from ECT, including anticonvulsants and some minor tranquilizers, may also need to be tapered or discontinued.


Accumulated clinical experience -- later confirmed in controlled clinical trials, which included the use of simulated or "sham" ECT as a control (Janicak et al., 1985), determined ECT to be highly effective against severe depression, some acute psychotic states, and mania (Small et al., 1988).

No controlled study has shown any other treatment to have superior efficacy to ECT in the treatment of depression (Janicak et al., 1985; Rudorfer et al., 1997). ECT has not been demonstrated to be effective in dysthymia, substance abuse, anxiety, or personality disorders. The foregoing conclusions, and many of those discussed below, are the products of review of extensive research conducted over several decades (Depression Guideline Panel, 1993; Rudorfer et al., 1997) as well as by an independent panel of scientists, practitioners, and consumers (NIH & NIMH Consensus Conference, 1985).

Although the average 60 to 70 percent response rate seen with ECT is comparable to that obtained with pharmacotherapy, there is evidence that the antidepressant effect of ECT occurs faster than that seen with medication, encouraging the use of ECT where depression is accompanied by potentially uncontrollable suicidal ideas and actions (Rudorfer et al., 1997). However, ECT does not exert a long-term protection against suicide. Indeed, it is now recognized that a single course of ECT should be regarded as a short-term treatment for an acute episode of illness. To sustain the response to ECT, continuation treatment, often in the form of antidepressant and/or mood stabilizer medication, must be instituted (Sackeim, 1994).

Individuals who repeatedly relapse following ECT despite continuation medication may be candidates for maintenance ECT, delivered on an outpatient basis at a rate of one treatment weekly to as infrequently as monthly (Sackeim, 1994; Rudorfer et al., 1997).

Informed consent

Informed consent is an integral part of the ECT process (NIH & NIMH Consensus Conference, 1985). The potential benefits and risks of this treatment, and of available alternative interventions, should be carefully reviewed and discussed with patients and, where appropriate, family or friends. Prospective candidates for ECT should be informed, for example, that its benefits are short-lived without active continuation treatment, and that there may be some risk of permanent severe memory loss after ECT.

In most cases of depression, the benefit-to-risk ratio will favor the use of medication and/or psychotherapy as the preferred course of action (Depression Guideline Panel, 1993). Where medication has not succeeded, or is fraught with unusual risk, or where the potential benefits of ECT are great, such as in delusional depression, the balance of potential benefits to risks may tilt in favor of ECT.

Active discussion with the treatment team, supplemented by the growing amount of printed and videotaped information packages for consumers, is necessary in the decision-making process, both prior to and throughout a course of ECT. Consent may be revoked at any time during a series of ECT sessions.

Involuntary ECT

Severely depressed patients with psychomotor retardation sometimes have difficulty in understanding concepts and in agreeing to anything, let alone a complex procedure like ECT. The presence of psychosis can render informed consent impossible.

Procedures for involuntary ECT vary from country to country depending on local mental health laws. Legal proceedings are required in some countries whilst in others ECT is seen as another form of treatment that may be given involuntarily as long as legal conditions are observed.

In the United States, involuntary ECT may not be initiated by a physician or family member without a judicial proceeding. In every state, the administration of ECT on an involuntary basis requires such a judicial proceeding at which patients may be represented by legal counsel. As a rule, such petitions are granted only where the prompt institution of ECT is regarded as potentially lifesaving, as in the case of a person who is in grave danger because of lack of food or fluid intake caused by catatonia.

Australian states take the other approach and the law regards involuntary treatment with ECT in the same light as any other involuntary treatment. There is an appeal process available for patients and relatives. This position facilitates the expedited use of ECT in emergencies.

Continuation phase therapy

Successful acute phase antidepressant pharmacotherapy or ECT should almost always be followed by at least 6 months of continued treatment (Prien & Kupfer, 1986; Depression Guideline Panel, 1993; Rudorfer et al., 1997). During this phase, known as the continuation phase, most patients are seen biweekly or monthly.

The primary goal of continuation pharmacotherapy is to prevent relapse (i.e., an exacerbation of symptoms sufficient to meet syndromal criteria). Continuation pharmacotherapy reduces the risk of relapse from 40-60 percent to 10-20 percent (Prien & Kupfer, 1986; Thase, 1993). Relapse despite continuation pharmacotherapy might suggest either nonadherence (Myers & Branthwaithe, 1992) or loss of a placebo response (Quitkin et al., 1993a).

A second goal of continuation pharmacotherapy is consolidation of a response into a complete remission and subsequent recovery (i.e., 6 months of sustained remission). A remission is defined as a complete resolution of affective symptoms to a level similar to healthy people (Frank et al., 1991a). As residual symptoms are associated with increased relapse risk (Keller et al., 1992; Thase et al., 1992), recovery should be achieved before withdrawing antidepressant pharmacotherapy.

Many psychotherapists similarly taper a successful course of treatment by scheduling several sessions (every other week or monthly) prior to termination. There is some evidence, albeit weak, that relapse is less common following successful treatment with one type of psychotherapy—cognitive-behavioral therapy—than with antidepressants (Kovacs et al., 1981; Blackburn et al., 1986; Simons et al., 1986; Evans et al., 1992). If confirmed, this advantage may offset the greater short-term costs of psychotherapy.

Historical usage

ECT was developed in the 1930s by Italian neurologist Ugo Cerletti. Cerletti saw electric shocks given to hogs before slaughter. This rendered them unconscious but did not kill them. Cerletti found such electric shocks caused his obsessive and difficult mental patients to become meek and manageable.

When ECT was first instituted, the procedure was performed on fully conscious patients, without the use of anesthesia or muscle relaxants. The patient lost consciousness during the application of the current, and experienced powerful and violently uncontrolled muscle movement. Patients would often break bones, especially vertebrae, and pull muscles from the violent convulsions induced by the seizure. Patients grew to dread the procedure, and it was commonly employed as a means of punishment and sedation for difficult patients in psychiatric hospitals.

With the development of effective medications for the treatment of major mental disorders a half-century ago, the need for ECT lessened, but did not disappear. Prior to that time, ECT often had been administered for a variety of conditions for which it is not now generally regarded effective, for example, the treatment of schizophrenia.

Advances in treatment technique over the past generation have enabled a reduction of adverse cognitive effects of ECT (NIH & NIMH Consensus Conference, 1985; Rudorfer et al., 1997). Nearly all ECT devices deliver a lower current, brief-pulse electrical stimulation, rather than the original sine wave output; with a brief pulse electrical wave, a therapeutic seizure may be induced with as little as one-third the electrical power as with the older method, thereby reducing the potential for confusion and memory disturbance (Andrade et al., 1998).


In general, but with a small number of exceptions, there is some degree of consensus within the field of psychiatry as to the benefits of ECT. However, ECT remains a topic that can generate much debate in both the field of psychology and among the general public. While its effectiveness is reasonable, a large number of people within and outside the field regard it as inhumane and primitive -- even barbarous. The correlation between ECT and long-term recovery is comparatively weak, and most professionals would regard it as a last resort, if at all. Opponents claim that the mechanism through which electroshock creates changes in mental state is nothing more than the destruction of brain cells, and even proponents are not quite sure how it works. Many patients who have undergone ECT claim it caused their subsequent mental state to improve; many others think their ECT treatments did more harm than good, and some actively campaign to have the treatment legally banned.

The Church of Scientology's Dianetics claims that ECT does not treat the cause of the disorder but suppresses natural reactions to certain influences by creating further disorders. The CCHR, an institution set up by Scientology, also claims that the real nature of psychiatry is that of human rights abuse.

Antipsychiatry believes that, for the most part, there are no real mental illnesses and that ECT is used to suppress certain behaviors which, although perhaps uncommon, are still within the normal range. (See: Retraumatizing the victim (http://www.sidran.org/anna.html), Alan Turing and Case reports: restraint deaths & abuse (http://www.cchr.org/government/eng/page18.htm) for examples of such cases.)

Some question the effects of drugs on the ability to give informed consent.

The old method of performing ECT - without muscle relaxants or drugs to induce sleep - is what is responsible for the unfavorable reputation given to ECT. A great deal of anti-ECT sentiment was generated by its unfavorable depiction in the 1975 movie One Flew Over the Cuckoo's Nest, based on a novel by Ken Kesey, which in turn was based loosely on the author's own experiences in various mental hospitals during the 1960s. Other negative depictions, such as in the books Zen and the Art of Motorcycle Maintenance and The Bell Jar, as well as the movies Requiem for a Dream and A Beautiful Mind, have also furthered this negative stereotype.

The use of ECT has been banned in the Republic of Slovenia.

Ernest Hemingway, who underwent 20 ECT treatments, is known to have stated "Well, what is the sense of ruining my head and erasing my memory, which is my capital, and putting me out of business? It was a brilliant cure but we lost the patient...." He committed suicide shortly afterwards.

Alternative treatments

There is current research in using Magnetic stimulation therapy (MST) as an alternative to ECT. Omega-3 fatty acids and sleep deprivation are also being researched.

Relationship of ECT to Religious Practices for Inducing Ecstatic Seizures

The efficacy of ECT for treatment of severe depression have led some to speculate that the seizures observed in some forms of ecstatic religious practice, e.g. among the Holy Ghost, Slain in the Spirit, Shakers, Pentecostals, Shamanic, and Kundalini Yoga practitioners, are serving a similar function in relieving symptoms of depression. Those who support this view theorize that the evolution of such seizure-inducing practices, which is widespread among the world's religions, may have been selected for by an accidental process but remain as cultural traditions due to the emotional benefit the practitioners feel they receive. Some feel that candidates for ECT might benefit from participating in such religious practices if they have a prior religious predisposition.


Sections of this article were adapted from the public domain document Mental Health: a report of the Surgeon General, online at http://www.surgeongeneral.gov/library/mentalhealth/chapter4/sec3_1.html#treatment

External links

Studies in-progress:


nl:Elektroconvulsieve therapie


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