Capacity, competence, and who gets to decide

Capacity is not competence

The words get used interchangeably and they shouldn't be. Capacity is a clinical judgment: can this person make this particular decision, at this particular moment. Any physician can assess it, and psychiatrists are often asked to when the answer is contested. Competence is a legal status, determined by a court, and it carries consequences well beyond a single treatment decision.

Getting the distinction right matters, because a consult that asks "is this patient competent" is asking the wrong body the wrong question. What the team almost always needs is a capacity assessment about a specific decision in front of them.

The four abilities

The framework nearly everyone uses comes from Paul Appelbaum's 2007 clinical practice paper in the New England Journal of Medicine. It asks whether the patient can do four things:

• Communicate a choice. Can they express a decision and hold it long enough to act on it.
• Understand the relevant information: the condition, the proposed treatment, the alternatives, the risks of each, including doing nothing.
• Appreciate how that information applies to them. This is where it most often breaks down. A patient can recite the facts accurately and still not believe any of it is about them.
• Reason with the information: weigh the options against their own values and arrive at a conclusion by a process that makes sense.

Note what's absent from that list. Nowhere does it ask whether the patient agrees with you. A capacity assessment is about the process, not the verdict.

The sliding scale nobody writes down

In practice, the threshold moves with the stakes. Clinicians apply more scrutiny when a decision carries a high risk of serious harm and less when the consequences are modest. Consenting to a low-risk intervention gets a lighter touch than refusing one that's likely to be life-saving. This is defensible and widely practiced, but it's worth being honest that it introduces asymmetry: the bar tends to rise precisely when the patient disagrees with the team.

Capacity is also task-specific and it fluctuates. A delirious patient may lack it at midnight and have it by morning. Someone can have capacity to decide about a medication and lack it for a complex surgical decision. Assess the decision in front of you, at the time it's being made, and reassess.

The refusal problem

Here is the part that's genuinely hard. A patient with capacity can refuse treatment you're confident they need, and they can be right about their own life in ways you can't see from a chair in the unit. A diagnosis, even a severe one, doesn't remove capacity. Neither does an unwise choice. The bar is a process, not an outcome.

This is also where capacity and civil commitment get tangled. Being committed doesn't automatically mean a person can be medicated against their will. In many jurisdictions that's a separate legal question with its own process, and a capacitated refusal can survive the commitment. Detention and treatment are two different intrusions.

What good practice actually looks like

Assess the specific decision, not the person in general. Give the information in a form the patient can actually use, then ask them to explain it back rather than asking whether they understood. Probe appreciation directly, because that's the ability that most often fails quietly. Document your reasoning, not just your conclusion, since a note that says "patient lacks capacity" with nothing behind it is worth nothing to the next clinician and less than nothing in court.

And treat a capacitated refusal as an outcome the system is designed to permit rather than as a defeat. The profession's authority is real, and its limits are what keep it trustworthy. The ethics room in the Operating Room puts this alongside the rest of the lines that define the work.