ECT and Memory Loss

In the late 1940s and early ‘50s, the heyday of electroshock, memory loss induced by ECT was considered to be its therapeutic effect. The distressed subjects conveniently forgot what was upsetting them, such as war traumas, child abuse, rape, betrayal, or family violence. [Janis, 1948] When electroshock made a comeback, it needed a new PR image, helped immensely by the administration of muscle paralyzing agents so that the victim appeared to be peacefully asleep during the brutal procedure. A significant part of the cleanup effort was to assert that ECT did not cause significant or permanent memory loss.

To this day, the Mayo clinic patient information website on electroshock says, “…memory problems usually improve within a couple of months after treatment ends.” [Mayo 2019] This is in sharp contrast to abundant studies indicating that permanent memory deficits after ECT are not unusual. Some studies report that half or more of shock survivors have persistent memory loss. [Rose, 2004; Squire, 1977] The average person would not think that 50% suffering memory loss is what is meant by the Mayo’ s statement “memory problems usually improve.”

Electroconvulsive therapy, better known as shock treatment, is the process of applying electricity to the brain through electrodes attached to the head. The goal of shock treatment is to totally disrupt the normally orderly brain wave transmissions to create a brain seizure: an electrical storm seen on the wave tracing as a pattern-less chaos of undirected electricity. If the subject were not chemically paralyzed for the procedure, this would result in typical mouth clenching, back arching, and jerking and flailing of arms and legs.

Seizures from any cause are well known to impair memory. While memory deficits are common in people with epilepsy, memory loss can also happen after fever-related seizures (febrile seizures), and can even occur after a single seizure. [Holley, 2018; Trimble, 1986] Thus the entire goal of neurologists caring for such patients is to suppress seizures, more often than not at the cost of unpleasant medication side effects. But the drugs are considered preferable to the brain damaging effects of seizures, prime among them cognitive deficits related to impaired memory. The sole difference with shock therapy is that the seizures are caused intentionally, which does not at all diminish the hit on the brain as compared to spontaneous seizures.

Objective evidence of the persistent damaging effect of ECT on brain function is provided in part by brain wave testing with electroencephalogram (EEG). As seen in patients with epilepsy, brain wave activity tends to remain very abnormal between ECT sessions when shock treatment is delivered acutely. The abnormalities can even be characterized more precisely, such as in a study that correlated the specific type of memory loss to the location of abnormal brain waves on EEG. [Sackheim, 2000]

In a review of papers reporting on patients’ own views of their electroshock experiences, 20 studies were cited in which patients recognized memory loss as a consequence of the treatment. The review described significant memory loss was reported by 29% to 55% of recipients, depending on the study.  The paper details how the standard memory tests are faulty, failing to detect most of the significant memory problems that victims describe. [Rose, 2003]

As with any other form of brain injury, more ECT gives a greater risk of persistent memory loss. Nevertheless, severe memory loss can happen with less intensive treatment. The press reported on a 55-year old woman who suffered brain damage and lost 30 years of memories, including job skills and the births of her children. She had received 13 session of ECT in close succession, followed by 3 “maintenance” shocks in the following two weeks. In a lawsuit, an additional psychiatrist on her case was charged with failing to take steps to stop the shock doctor from giving more ECT after memory problems had become obvious. Much has been written about the factors that make brain damage more likely, but this victim received fewer than 20 shocks in total, had no underlying brain disease, and was not on particular psychotropic drugs that increase risk of adverse effects. [Grant, 2006]

Aside from using tests that don’t accurately detect memory problems, the medical literature cannot be fully trusted to give an accurate picture of long-term brain damaging effects from ECT. For example, a 2017 study was presented as if it were a conclusive answer to the memory question, reporting on 1,212 shock recipients of whom “only 26%” had memory loss. But they tested the subjects at one week after ECT, thus conveniently avoiding the issue of long-term memory loss entirely. [Brus, 2017]

Another common way to report lower numbers of apparent memory loss is to look at a wide mix of subjects, such as one study that looked at recipients of from 6 to 72 shocks, essentially a 9-fold difference in dosage.  In the world of drug testing, this would be equivalent to reporting drug side effects in patients on widely varying drug dosages, such as only 1/9 of the usual dose – that kind of research could not even get published due to dishonest study design, intended to understate the adverse effects. [MacQueen, 2007]

A particularly vicious way of reporting is for medical articles to disdainfully describe “perceived memory problems,” as if memory loss is not real unless the psychiatrist says it is. A study that reported half of shock survivors still complained of memory loss three years after ECT, characterized the subjects’ complaints as “a tendency to question if memory had ever recovered.” [Squire, 1977]

The most prevalent recurring theme in medical reports on ECT and memory loss is to lament that it is inadequately studied and poorly quantified – in other words, shock doctors have no accurate data on how many truly suffer memory loss and how severe it can be. [Semkovska, 2012; Prudic, 2000] This would be a crucial piece of information in a full process of Informed Consent.

To quote one researcher:

“This major gap in our knowledge prevents us at present from objectively quantifying the nature and extent of [memory loss] associated with ECT.” [Semovska, 2012]

The potential for memory loss from ECT is virtually always couched in soothing terms, likening it to the risks of “any other medical procedure.” Patients, and physicians who are the referral sources to shock docs, are typically told that “some” experience long-term memory loss, but that memory “usually” recovers. [MacDonald, 2016, on APA website] There is no communication about exiting reports of long-term memory loss in up to over 50%, or the insufficiency of studies quantifying the overall risks.

In addition, the significant implications of the differing types of memory loss are never discussed. Retrograde amnesia is loss of memory for things that happened or were learned before brain damage. This often includes autobiographical information such as where one has lived, significant life events, basic technical skills like spelling and arithmetic, artistic talents and job skills. Anterograde amnesia is the inability to form new memories or to retain learning after brain damage. Combined, these types of memory loss can lead to a crisis of self-identity, chronic subtle or not-so-subtle disorientation, and loss of decision-making capacity.

Among providing other facts of ECT, Informed Consent should include the basic information that memory is insufficiently studied but has been described in up to over 50% of survivors, that the brain waves stay abnormal between ECT sessions and correlate with type of memory problems, along with a description of anterograde, retrograde, and autobiographical memory deficits and their potential effects on functioning in life after ECT.


Janis IL. Memory loss following electric convulsive treatments. V. J Pers. 1948;17:29–32.

Mayo Clinic website, “Electroconvulsive Therapy,” Last accessed: 4/14/2019:

Holley AJ, Hodges SL, Nolan SO, et al. A single seizure selectively impairs hippocampal-dependent memory and is associated with alterations in PI3K/Akt/mTOR and FMRP signaling. Epilepsia Open. 2018;3(4):511–523.

Grant, JE. ECT wipes out 30 years of memories. Current Psychiatry. Vol. 5, No. 8, August 2006.

Rose D,  Fleischmann P,   Wyke T,  Leese M, Bindman J. Patients’ perspectives on electroconvulsive therapy: systematic review. BMJ 2003;326:1363

Brus O et al. Subjective memory immediately following electroconvulsive therapy. J ECT 2017 Jun; 33:96. (

MacQueen G, Parkin C, Marriott M, Bégin H, Hasey G. The long-term impact of treatment with electroconvulsive therapy on discrete memory systems in patients with bipolar disorder. J Psychiatry Neurosci. 2007;32(4):241-9.

Sackeim HA, Luber B, Moeller JR, Prudic J, Devanand DP, Nobler MS. Electrophysiological correlates of the adverse cognitive effects of electroconvulsive therapy. J ECT. 2000 Jun;16(2):110-20.

Maria Semkovska;Declan McLoughlin; Measuring Retrograde Autobiographical Amnesia Following Electroconvulsive Therapy: Historical Perspective and Current Issues. The Journal of ECT. 29(2):127–133, JUN 2013.

William McDonald, M.D. Laura Fochtmann, M.D. What is electroconvulsive therapy (ECT)? Section on Risks & benefits. Physician Review – January 2016. APA website, Last accessed: 4/15/2019.

Trimble MR, Thompson PJ (1986) Neuropsychological and behavioral sequelae of spontaneous seizures. Ann N YAcad Sci 462:284-292.

Additional reading:
Boyles, S. Memory Loss Common Complaint With ECT.  WebMD Archives. June 19, 2003. At

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