Electroconvulsive therapy (ECT) is primarily used to treat severe depression, particularly when medications and other treatments have failed. It’s also one of the most effective treatments available for catatonia, severe mania in bipolar disorder, and agitation in dementia. Despite its stigmatized reputation, ECT remains a frontline option when speed matters, such as when someone is actively suicidal or unable to eat or move.
Conditions ECT Treats
The most common reason someone receives ECT is treatment-resistant depression, meaning depression that hasn’t improved after trying multiple medications or therapies. ECT is also used for severe depression accompanied by psychosis (a break from reality), strong suicidal intent, or physical decline from refusing food and water.
Beyond depression, ECT treats several other conditions:
- Severe mania in bipolar disorder, especially when someone is dangerously agitated, behaving recklessly, or experiencing psychosis.
- Catatonia, a condition involving an inability to move, speak, or respond, or alternatively, strange repetitive movements. Response rates for catatonia range from 80 to 100 percent, even when sedative medications haven’t worked. In life-threatening forms like malignant catatonia, ECT is considered a first-line treatment.
- Agitation and aggression in dementia, particularly when behavioral approaches and medications haven’t helped.
ECT is sometimes recommended during pregnancy, when psychiatric medications carry risks to the developing fetus. It’s also an option for older adults who can’t tolerate drug side effects, or for anyone who has responded well to ECT in the past and prefers it over medication.
How Effective ECT Is
For treatment-resistant depression, ECT consistently outperforms other interventions. In a large multicenter trial, ECT achieved a remission rate of about 63 percent compared to 46 percent for ketamine infusions. When compared to repetitive transcranial magnetic stimulation (rTMS), a non-invasive brain stimulation alternative, ECT produced response rates of 38 percent versus 15 percent, with substantially greater reductions in depression scores.
That said, not every study shows the same gap. One trial found ketamine and ECT had comparable response rates (55 percent for ketamine versus 41 percent for ECT), though the study’s design measured slightly different outcomes. Overall, ECT is considered the most potent acute treatment for severe depression, particularly when rapid improvement is critical.
How the Procedure Works
Modern ECT looks nothing like its portrayal in older films. You’re placed under general anesthesia, typically with a fast-acting barbiturate, and given a muscle relaxant to prevent physical movement during the procedure. You’re asleep the entire time and feel nothing.
Once you’re anesthetized, a brief electrical current is delivered to the brain through electrodes placed on the scalp. This triggers a controlled seizure lasting roughly 30 to 60 seconds. The seizure itself is the therapeutic element. Your body barely moves because of the muscle relaxant, and the whole session, from anesthesia to waking up, takes about 15 to 20 minutes.
A typical acute course involves two to three sessions per week over several weeks, usually six to twelve sessions total. Your treatment team adjusts the number based on how quickly symptoms improve.
Electrode Placement Matters
Where the electrodes are placed on your head affects both how well ECT works and how it impacts memory. The two main options are right unilateral (both electrodes on the right side of the head) and bitemporal (one on each side).
When right unilateral ECT is delivered at a high enough dose, it works just as well as bitemporal ECT for depression. The advantage is fewer cognitive side effects. People who receive unilateral ECT recover their orientation faster after each session (about 19 minutes versus 26 minutes) and retain more autobiographical memories both immediately after treatment and at the six-month mark. They also report fewer subjective cognitive complaints.
What Happens to Memory
Memory effects are the most discussed side effect of ECT and the primary concern for most people considering it. The reality is more nuanced than the common fear suggests.
In a large study that followed up with patients roughly two to three months after their last session, about 52 percent reported no change in their memory, 31 percent said their memory had actually improved (likely because severe depression itself impairs memory), and 16 percent reported that their memory had worsened. Of those who felt their memory was worse, only about 8 percent of the total group described the impairment as clinically significant.
The memory problems that do occur typically fall into two categories. One is difficulty remembering events from the weeks surrounding the treatment period, a phenomenon called retrograde amnesia. The other is temporary trouble forming new memories in the days after a session. Both tend to improve over the weeks following a course of ECT. An earlier study using the same assessment tool found 25 percent of patients reported memory worsening immediately after ECT, compared to 16 percent at later follow-up, suggesting the effects fade with time.
Interestingly, people who had more negative expectations about ECT beforehand were more likely to report memory worsening afterward, and younger patients were more affected than older ones.
How ECT Changes the Brain
Scientists don’t fully understand why inducing a seizure relieves depression, but the leading explanation is the neuroplasticity hypothesis. The idea is that ECT stimulates the brain to grow new neurons and form new connections between existing ones. Animal research shows that ECT increases levels of proteins involved in cell growth and strengthens signaling pathways that support brain cell survival.
One key protein, brain-derived neurotrophic factor (BDNF), which acts like fertilizer for brain cells, tends to increase after ECT. Neuroimaging studies also show that ECT changes how different brain networks communicate with each other, though these changes are complex and still being mapped out. The neurotransmitter effects of ECT (changes in chemical messengers like serotonin and dopamine) have been studied extensively, but the evidence on exactly which chemical shifts matter most remains inconsistent.
Staying Well After ECT
One of the biggest challenges with ECT is maintaining the improvement it produces. Without any follow-up treatment, roughly 38 percent of people relapse within six months, and about 51 percent relapse within a year. Most relapses happen in the first three months.
To prevent this, doctors typically recommend either maintenance medication, ongoing ECT sessions, or both. Maintenance ECT involves continuing treatments at gradually increasing intervals, often starting at once a week and stretching to once every three to six weeks. In one study, patients receiving maintenance ECT were treated at a median frequency of once every three weeks over about a year.
Even with maintenance ECT, stopping treatment carries risk. When maintenance ECT is abruptly discontinued, about 44 percent of patients relapse within six months, with half of those relapses occurring in the first eight weeks. This is why treatment teams generally taper or transition patients carefully, though tapering a treatment that’s already spaced weeks apart presents its own challenges.
Who Can Safely Receive ECT
ECT has no absolute medical contraindications, meaning there is no condition that automatically rules it out. However, certain situations require extra caution. Conditions that raise pressure inside the skull, like certain brain tumors, increase the risk significantly. Cardiovascular problems also need careful evaluation, since the seizure temporarily raises heart rate and blood pressure.
ECT is considered safe across the lifespan, from adolescents to older adults, and has been studied in pregnant patients without evidence of harm to the fetus. For older adults in particular, ECT can be safer than polypharmacy (taking multiple psychiatric medications), since it avoids the drug interactions and side effects that accumulate with age.