Yes—someone with dementia can still make decisions about a living will if they have capacity for that particular decision when they make it. A dementia diagnosis alone does not remove that ability. A living will is an advance directive stating which emergency or life-sustaining treatments a person wants or refuses if they can no longer decide. It may address CPR, mechanical ventilation, and feeding tubes.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- Dementia does not automatically mean incapacity
- What must the person be able to decide?
- How to complete or change a living will
- What happens after capacity is lost?
Dementia does not automatically mean incapacity
Capacity depends on the person's abilities, not simply a diagnosis or disease stage. The person must be assessed in relation to the decision they are making at that time. Capacity is also decision-specific. According to the U.S.
Department of Veterans Affairs guidance on appointing a health-care agent, someone may be able to choose an agent even if they cannot consent to a treatment. Giving detailed instructions about future treatments requires a separate assessment. This distinction matters in mild-to-moderate dementia. Many people can still express whom they trust to make health-care decisions, even when complex medical choices have become difficult.
What must the person be able to decide?
The key question is whether the person can understand, choose, and sign the document. The assessment should focus on the actual instructions being considered, rather than testing general knowledge or memory alone. For example, someone might consistently choose a trusted daughter as a health-care agent but struggle to understand detailed choices about ventilation or feeding tubes.
That person may retain capacity for the first decision but not the second. A health-care agent and a living will serve different purposes. The living will records treatment preferences, while the agent makes future decisions intended to carry out the person's wishes. A person who can still choose an agent may therefore complete that part of advance planning even if detailed treatment instructions are no longer appropriate.
How to complete or change a living will
Start advance-care planning as early as possible. The National Institute on Aging's guidance on planning with people who have dementia supports involving the person while their cognitive state still allows them to describe their values, goals, and preferred decision-makers.
Practical steps include: State requirements differ. The VA's advance-directive information advises using the applicable state form and obtaining help from a clinician or qualified legal professional when capacity or signing is disputed.
- Discuss the person's goals and treatment preferences while they can participate.
- Decide whether to document treatment instructions, appoint a health-care agent, or do both.
- Use the advance-directive form and signing process required by the applicable state.
- Seek help promptly if anyone questions the person's capacity or the document's execution.
What happens after capacity is lost?
Once the person can no longer understand, choose, or sign, an existing advance directive can guide clinicians and family. A named health-care agent can then make decisions intended to follow the person's documented wishes. Without an advance directive, state law determines who may make medical decisions.
The default is often a spouse, available parents, or adult children, but the order and authority differ by jurisdiction. Even a legally recognized directive cannot guarantee that every instruction will be followed exactly. The National Institute on Aging's advance-care-planning guidance notes that circumstances, institutional policy, clinician conscience, or accepted standards of care may prevent compliance; providers should notify the proxy and consider a transfer.
