do 18% of ect patients at camh report memory problems, with half then stopping?
“at CAMH, the commonly quoted statistics, about 18% of people have some type of memory impairment. About half of them continue on with ECT, and half of them consider it a deal breaker.”
a guest, a psychiatrist said on PsychEd: Educational Psychiatry Podcast, 2026-11-01, at 56:16. hear it in context → the speaker cited: commonly quoted CAMH statistics.
the episode: PsychEd Case Rounds 1 with Dr. David Gratzer (at 56:16). we link the show's own page; we do not re-host audio.
first, the part that holds
the 18% figure is in the right range. a published chart review from CAMH found that about 17% of patients (40 of 238) had cognitive impairment recorded during an acute ECT course, and a large Swedish study found subjective memory got worse in 16% of patients. the second half of the claim, that half of those patients keep going and half stop, has no published source we could find.
what we found when we went and looked
we couldn't find a published CAMH statistic that matches the claim. the closest record is a 2020 CAMH chart review of 238 inpatients with schizophrenia treated with ECT between 2010 and 2018. it recorded cognitive impairment in 21 of 159 patients judged incapable of consenting (13.2%) and 19 of 79 capable patients (24.1%), about 16.8% overall. that is close to 18%, but it counts clinician-noted cognitive effects rather than memory complaints reported by patients, and it covers only people with schizophrenia. it also never reports how many of those patients carried on with ECT versus stopping, so the half-and-half split has no source we can check. measurement method changes the number a lot: in a Swedish multi-site study, 16.2% got worse when memory was compared before and after treatment, but 54.6% said ECT had harmed their memory when asked afterward.
assertion by assertion
| assertion | verdict | what the record says |
|---|---|---|
| at CAMH, about 18% of ECT patients have some type of memory impairment | unverifiable | no published CAMH memory-specific figure found. the nearest CAMH record (schizophrenia chart review, 2010-2018, n=238) recorded cognitive impairment in 40 patients (16.8%; 13.2% of incapable and 24.1% of capable patients). this figure is close to the claim, but it is clinician-noted cognition, from charts, in one diagnosis only. [1] |
| about half of those with memory impairment continue ECT and half consider it a deal breaker | unverifiable | none of the sources we read reports this split. in the CAMH chart review, 'early stoppage or modification' of the course is one of the criteria for rating cognitive impairment, but the number of patients who stopped is not reported separately. the reviews we read report satisfaction with ECT anywhere from 36% to 98%, never refusal because of memory. [1][4] |
| a figure near 18% for memory worsening fits other prospective studies | confirmed | Swedish PREFECT study (8 hospitals, n=277, follow-up a median of 73 days after the last session): memory worsened in 16.2% when compared before and after treatment, and 7.9% had clinically significant worsening. a systematic review cites 26% worse within a week in a Swedish registry study (n=1212) and 28% in another Swedish sample. [2][3][4] |
| how patients are asked changes the rate | undersold | in the same Swedish sample, 54.6% said ECT had a negative effect on their memory when asked afterward, more than three times the 16.2% found by comparing before and after. a Nigerian study cited in the review found 37.1% reported memory problems at 6 months. if 'memory impairment' means what patients say about their own memory, 18% is at the low end. [2][3][4] |
both directions
for the speaker: CAMH's own published chart review gives a cognitive-impairment rate of about 17%, within a point of the claim. prospective before-and-after studies elsewhere also land between 16% and 28%. the CAMH paper also shows that cognitive effects sometimes led to a course being stopped early or changed, so some patients do treat it as a deal breaker.
against: the claim is framed as a 'commonly quoted' CAMH statistic, but no published CAMH source in the primary record matches it. the nearest CAMH figure covers people with schizophrenia only and records cognition broadly, not memory as patients report it. nothing we read supports the half-continue, half-stop split. asked afterward, a majority of patients (54.6% in the largest recent prospective study) say ECT hurt their memory, so 18% can understate how many patients feel affected.
what this cannot say
the figure may come from internal CAMH audit data, consent materials or clinical experience that was never published. we can't check any of that, so the verdict is UNVERIFIABLE, not FALSE. the CAMH chart review depends on what clinicians wrote down, which probably misses mild or delayed complaints. we found that study by search and read its PMC record; the summary we read did not itself restate the CAMH setting. the Swedish study lost about half of its enrolled patients before follow-up. measures, stimulus types and follow-up times vary widely across studies, and the review we read says the variation is too large for a pooled figure. we did not search unpublished conference abstracts.
sources, each one fetched and read
- Treatment capacity and clinical outcomes for patients with schizophrenia who were treated with electroconvulsive therapy: a retrospective cohort study. Schizophrenia Bulletin, 2020. PMC7965065 What we read there: 238 patients (159 incapable, 79 capable); cognitive impairment in 21/159 (13.2%) incapable and 19/79 (24.1%) capable patients, P = .043; impairment rated moderate/severe if described as significant, caused distress, led to early stoppage or modification of ECT, or caused functional difficulty. discontinuation not reported separately. Fetched 2026-11-01 (HTTP 200). https://pmc.ncbi.nlm.nih.gov/articles/PMC7965065/
- Long-term subjective memory after electroconvulsive therapy (PREFECT project). BJPsych Open, 2020. PMC7176828 What we read there: 8 Swedish hospitals, n=277; pre/post memory improved 31.4%, unchanged 52.3%, worsened 16.2%, clinically significant worsening 7.9%; 54.6% reported a negative effect of ECT on memory when asked afterward; follow-up a median of 73 days after the last session. Fetched 2026-11-01 (HTTP 200). https://pmc.ncbi.nlm.nih.gov/articles/PMC7176828/
- Subjective memory impairment after electroconvulsive therapy – potentially modifiable? BJPsych Open editorial, 2020. PMC7189405 What we read there: 16.2% showed worsening in subjective memory between baseline and post-ECT, while 54.5% reported negative effects when rating ECT's impact on memory; about 48% of participants could not be included in the final analysis. Fetched 2026-11-01 (HTTP 200). https://pmc.ncbi.nlm.nih.gov/articles/PMC7189405/
- Subjective memory complaints after electroconvulsive therapy: systematic review. BJPsych Bulletin, 2019;43:73-80. doi:10.1192/bjb.2018.45. PMC6472304 What we read there: 16 studies, considerable heterogeneity; Swedish registry (n=1212) 26% worse subjective memory within a week; another Swedish sample 28% worse; Nigerian study 37.1% at 6 months vs 22.6% controls; satisfaction after ECT 36% to 98%; no refusal rates attributable to memory reported. Fetched 2026-11-01 (HTTP 200). https://pmc.ncbi.nlm.nih.gov/articles/PMC6472304/
speakers are described by role, not named. one sentence is quoted under fair use, with attribution and a link to the original at the timestamp; we do not re-host audio or video. nothing on this page is a reason to start, stop or change a medication. if you have the file behind anything marked unverifiable, the research board is where people can answer. adam