ECT Is Not What You Think: A Century of Drift from Back Room to Routine Treatment
Modern ECT is a procedure performed under anesthesia and muscle relaxants, with strong efficacy, but the evidence on memory-loss side effects is still not fully clear, and social misunderstanding has left it over-stigmatized.
The video won't play here. Listen to the audio instead:
The argument · tap a timestamp to hear it
What actually happens if you or I get ECT
If you or I were to receive ECT, here is how it goes: first a risk assessment and informed consent, then a physical exam, then an overnight fast. The next morning, in the hospital or an outpatient clinic, an IV line is placed along with two blood pressure cuffs (arm and right leg), and EKG, EEG and EMG leads are connected. After the anesthesiologist puts you to sleep, the leg cuff is inflated to restrict blood flow to the right foot, then a muscle relaxant such as succinylcholine is given. Once the muscles are fully relaxed, a bite block is placed, and then a brief pulse of current is delivered through the electrodes (lasting seconds, even half a second). The goal is not to make your whole body convulse, but to induce a generalized seizure, typically lasting 25-70 seconds. Because the muscles are relaxed, you see almost no external movement — the whole thing is obvious on the EEG.
— Erin Allman-UpdikeElectrode placement, and why the right side comes first
There are several electrode placements: bitemporal (like in the movies), bifrontal, and most commonly 'right unilateral' — one electrode on the right temple, the other on the right side of the top of the head. Right unilateral is used for most people because it produces fewer cognitive side effects. Why consider the right side first? Because for about 98% of right-handed people and 70%-90% of left-handed people, language function sits in the left temporal lobe. Avoiding electrical stimulation on the left side theoretically reduces language-related memory problems. But right unilateral is slightly less effective than bilateral. During a course of treatment, doctors switch based on side effects and efficacy: if bilateral side effects are heavy, switch to right unilateral; if right unilateral is not working well, switch to bilateral.
— Erin Allman-UpdikeSeizure threshold and the effective dose
The seizure threshold is the minimum amount of current that can induce a seizure. There is no precise measuring device, so you start by estimating from age, then probe upward from a low dose until a seizure appears. But treatment does not stop at merely reaching threshold — the effective dose is usually 2.5 to 5 times the threshold. With bilateral, 2.5 times is enough, while right unilateral needs 5 times, because unilateral stimulation has a harder time achieving the same effect. The dose varies from person to person and has to be adjusted as you go. If in one session a patient's seizure does not occur or does not last long enough (less than 25 seconds), the doctor may increase the dose and try again. Treatment is generally three times a week, with a full course of 6 to 18 sessions, sometimes longer.
— Erin Allman-UpdikeWe still do not know exactly how ECT works
Why does shocking the brain treat depression and catatonia? Frankly: we still do not fully understand. There are several main hypotheses. One is neurotransmitter change: after ECT, serotonin, dopamine and GABA (an inhibitory transmitter) all change markedly. The rise in GABA is itself anticonvulsant, which could explain why the seizure threshold rises and seizures get shorter over a course of treatment. Two, large fluctuations in hormones such as ACTH, prolactin and TSH are seen in the hypothalamus and pituitary. Three, ECT promotes neurogenesis, with BDNF (brain-derived neurotrophic factor) as a key molecule. But how these changes directly relieve symptoms still has no one-to-one mechanism. Different illnesses (depression, schizophrenia, catatonia) may also work through different mechanisms, and for now we can only keep researching.
— Erin Allman-UpdikeDepression data: far better than first-line antidepressants
For treating severe depression, ECT's key data are quite strong: most studies report remission rates (symptoms fully gone) of 50%-60%, and response rates (symptoms clearly improved) of 60%-90%. By comparison, the best remission rate for SSRI antidepressants is only about 40%. ECT has another uncommon benefit — it can cut the 30-day readmission rate in half. This is not to say it should be first choice, nor that it has no risks (relapse or symptom rebound within 6-12 months is still not rare); but in patients with treatment-resistant depression combined with severe suicide risk, these efficacy advantages are hard to ignore.
— Erin WelshMemory problems draw the most attention among side effects
ECT's most difficult side effects center on cognition and memory. Right after the procedure there is brief confusion lasting from a few dozen seconds to half an hour, and for weeks there may be declines in attention and executive function. Interestingly, most cognitive function actually improves in the long term — possibly because the depression improves. The real trouble is memory. Anterograde amnesia (difficulty forming new memories) mostly recovers within a few weeks after the course ends, which is why many people are restricted from driving or making major decisions during treatment. Retrograde amnesia (losing past memories) is what worries patients more: it usually affects recall of the most recent months or even years before treatment, and in most cases recovers, but in some it is permanent. Bilateral treatment is more likely to cause this problem than right unilateral.
— Erin Allman-UpdikeCatatonia: a deadly syndrome that is often misread
Catatonia is often simply lumped in as a subtype of schizophrenia, but it is actually a psychomotor syndrome that any psychiatric or neurological illness can trigger. Patients appear awake, eyes open, yet are almost completely motionless and mute, and may show posturing or waxy flexibility (an arm placed in a position stays there). Because they cannot eat or drink and do not move for long periods, they are prone to malnutrition, pressure sores, muscle contractures, and even death. Untreated catatonia has a mortality rate as high as 20%! The most common treatment is benzodiazepines, but ECT is extremely effective in catatonia from many causes. The girl mentioned earlier with anti-NMDA receptor encephalitis (the 'Brain on Fire' case) developed catatonia; immunotherapy and lorazepam both failed, and she ultimately recovered with ECT.
— Erin Allman-UpdikeThe biggest bottleneck is not efficacy but access
Dr. Lopez believes the biggest obstacle ECT currently faces is finding a place to get it. His hospital performs more than 6,000 treatments a year across two campuses, averaging about 10-12 per patient. But it is not widely available across the US, and adults and children traveling across state lines for care are not few — especially in infants, children and adolescents with catatonia from autoimmune encephalitis, where finding an experienced treatment team is extremely hard. So improving access is his greatest hope. At the same time, doctors on other internal medicine, pediatric and critical care teams often do not recognize catatonia and do not dare, or do not think, to call an ECT consult; so 'preaching' to non-psychiatric colleagues is also part of his daily work.
— Leonardo LopezIn their own words · checked verbatim
The short answer to how does this work is that we still don't really know.
Erin Allman-Updike20:22
When we compare this to SSRIs, which we talked about in a prior episode, they have a remission rate at best of around 40 percent.
Erin Welsh24:24
The most common indication is for treatment-resistant depression, patients who have depression and have received medication for depression therapy and have not responded and remain ill.
Leonardo Lopez42:29
We use it in catatonia, which is a neuropsychiatric condition characterized by changes in speech and motor behavior that sort of spans a number of diagnoses.
Leonardo Lopez43:31
The more that we're able to show our colleagues in other fields the value of this treatment, the more they support it. I think that's been a big reason why we have tried at my hospital to sort of be very forward-facing with other departments.
Leonardo Lopez47:35
I think the biggest limitation is access to treatment without question.
Leonardo Lopez48:36
Figures
| Mortality rate of untreated catatonia | as high as 20% | 36:58 |
| Remission rate of ECT for severe depression | 50%-60% | 24:24 |
| Response rate of ECT for severe depression | 60%-90% | 24:24 |
| Best remission rate for SSRI antidepressants | about 40% | 24:24 |
| Reduction in 30-day readmission rate with ECT | about half | 25:00 |
| Share of right-handed people with language function in the left temporal lobe | about 98% | 15:17 |
| Share of left-handed people with language function in the left temporal lobe | 70%-90% | 15:17 |
| Typical duration of an ECT seizure | 25-70 seconds | 12:15 |
| Annual ECT treatments at Lopez's two campuses | more than 6,000 | 45:33 |
| Average number of ECT treatments per patient | 10-12 | 44:31 |
Glossary
- Catatonia
- A syndrome marked by prominent abnormalities in motor behavior and speech, which can be triggered by many psychiatric or neurological illnesses and is life-threatening in severe cases.
- Anti-NMDA receptor encephalitis
- An autoimmune encephalitis that often presents with seizures, psychiatric symptoms and catatonia, and requires immunotherapy for treatment.
- Succinylcholine
- A muscle relaxant used in ECT that blocks neuromuscular transmission, preventing strong whole-body convulsions during the electrical stimulus.
- Retrograde amnesia
- Loss of previously formed memories, most often for events from months to years before ECT.
- Transcranial magnetic stimulation (TMS)
- Uses magnetic pulses to induce weaker currents in the brain without causing seizures; side effects are mild but efficacy is usually weaker than ECT.
How to listen
Clinicians, psychiatric and pediatric staff, medical students, and anyone who has doubts about ECT or wants to understand the evidence behind first-line treatment.
The early history build-up can be skimmed; but the case examples in the treatment-procedure section are essential.