This is the part of ECT people find most uncomfortable, and it deserves a straight answer rather than avoidance.
Some people become so unwell that they cannot weigh up a treatment decision, a state clinicians describe as lacking capacity. Researchers at a single centre compared outcomes for 175 patients receiving ECT for schizophrenia, depression or mania. Of those, 75.1% lacked capacity to consent at the time.
Before treatment, that group had poorer thinking and general functioning. After ECT, symptom ratings improved similarly across both groups. Mood, thinking, quality of life and day-to-day functioning all improved in both, with greater gains in mood and functioning among those who had lacked capacity.
The authors are careful about the limits. Thinking was measured with a general screening tool rather than full neuropsychological testing, and the groups were too small to break down by diagnosis.
What the study offers is some reassurance about a genuinely difficult situation. Families are sometimes required to be involved in decisions for someone too unwell to make them, and this suggests people treated in those circumstances do improve, including in the abilities that allow them to make their own decisions again.
What "capacity" means here
In medicine, capacity refers to a person's ability, at a given moment, to understand relevant information about a treatment, weigh it against their own values, and communicate a decision. It is decision-specific and can change over time — someone might lack capacity to consent to ECT while acutely unwell, then regain it as they improve. When a person lacks capacity, clinicians must rely on substitute decision-making frameworks (such as family consent or independent panels) acting in the person's best interests. ECT itself involves passing a brief electrical current through the brain under general anaesthesia to trigger a controlled seizure, and is used for severe depression, mania and schizophrenia when other treatments haven't worked or urgent improvement is needed.
What this study did
Tor et al. followed 175 patients prescribed ECT at a single treatment centre, measuring symptoms, cognition (thinking and memory), quality of life and everyday functioning before and after treatment. Because this was an observational study rather than a randomised controlled trial (where patients are randomly assigned to different treatments to rule out other explanations), everyone received ECT — the comparison was between those who had capacity to consent and those who didn't.
Changes over time within each group were tested using repeated-measures ANOVA, a statistical method that checks whether average scores shift significantly across multiple time points for the same people. Differences between the two groups were tested with independent t-tests (for numeric measures like age or scores) and chi-squared tests (for categories like diagnosis) — both standard tools for asking whether two groups differ more than you'd expect by chance.
What it found
75.1% of the 175 patients lacked capacity at the time of treatment. Before ECT, this group had poorer cognition and global functioning, but higher quality-of-life ratings than the group with capacity — an interesting mismatch between self-rated wellbeing and more objective measures. After ECT, psychiatric symptoms improved to a similar degree in both groups. Mood, cognition, quality of life and functioning all improved in both groups, but mood and functioning improved more in the group that had lacked capacity. There was also a trend toward greater cognitive improvement in this group, with a p-value of 0.051 — just above the conventional 0.05 threshold researchers use to call a result "statistically significant." This means the finding is suggestive of a real difference but doesn't quite meet the usual bar for confidence, so it's best read as a hint worth further study rather than a settled result.
Why it matters, and its limits
These findings offer evidence-based reassurance for a genuinely difficult ethical situation: people treated with ECT under substitute decision-making arrangements appear to benefit at least as much as, and on some measures more than, those who consented themselves. The authors are transparent about constraints: cognition was measured with a brief screening tool rather than detailed neuropsychological testing, so subtler cognitive effects may have been missed. The sample was also too small to compare results separately by diagnosis (schizophrenia, depression, mania), and being a single-centre, non-randomised study, other factors specific to that setting could have influenced results.
If you or someone you know is dealing with severe mental illness and treatment decisions feel overwhelming, please reach out to a mental health professional — support and good information can make a real difference.