History and Future of ECT, With John J. Miller, MD, and Michael Henry, MD

TALKING WITH TITANS

John Miller, MD, sat down with Michael Henry, MD, on the history, mechanism, modern refinements, and future directions of electroconvulsive therapy (ECT).

Henry traced ECT's origins to a Hungarian psychiatrist who observed an inverse relationship between glial cell density in schizophrenia and seizure disorders, prompting experimental convulsive therapy, and to 2 Italian physiologists who substituted electrical induction for camphor after observing electrical stunning in a pig slaughterhouse.¹ The transition from continuous sine wave to brief- and ultra-brief-pulse stimulation markedly reduced excess brain heating and cognitive side effects while preserving seizure induction, which Henry emphasized remains necessary for therapeutic efficacy.

Henry described the dramatic safety improvement from the introduction of anesthesia—reducing the incidence of fractures, dislocations, and cardiac events from approximately 40% to less than 0.4%—and discussed the shift in electrode monitoring from isolated limb observation to continuous EEG, targeting a minimum seizure duration of 20 seconds.² He acknowledged persistent stigma rooted in cultural representations, and credited nursing staff as the "real secret weapon" in guiding patients through treatment.

On the relationship between ECT and newer neuromodulatory and pharmacological treatments, Henry described transcranial magnetic stimulation as complementary—particularly in elucidating mood circuit targets applicable to ECT electrode placement—and ketamine as demonstrating comparable antidepressant efficacy to ECT in head-to-head trials, with patient age emerging as a practical differentiator: older patients tend to respond better to ECT, younger patients to ketamine. He framed esketamine and racemic ketamine as acting through complementary mechanisms and noted unresolved questions about R-ketamine's independent antidepressant potential.

Looking ahead, Henry described machine learning analyses of a richly phenotyped McLean Hospital database—incorporating depression rating scales and the BASIS-32—as a first step toward predictive treatment matching, with polygenic risk scores and other biomarkers as potential enhancements. He noted that head-to-head ECT and ketamine trials have consistently demonstrated noninferiority of each to the other, suggesting that treatment selection algorithms face a substantial challenge, but that the goal of precision-matched neuromodulatory care remains clinically compelling.

Dr Henry is director of electroconvulsive therapy and associate professor of psychiatry at Harvard Medical School and Massachusetts General Hospital.

Dr Miller is Medical Director, Brain Health, Exeter, New Hampshire; Editor in Chief, Psychiatric Times; Volunteer Consulting Psychiatrist, Seacoast Mental Health Center, Exeter; Consulting Psychiatrist, Insight Meditation Society, Barre, Massachusetts.

References

1. Gazdag G, Ungvari GS. Electroconvulsive therapy: 80 years old and still going strong. World J Psychiatry. 2019;9(1):1-6.

2. Joung KW, Park DH, Jeong CH, et al. Anesthetic care for electroconvulsive therapy. Anesth Pain Med. 2022;17:145-156.