Mental Capacity Act 2005

Explains how the Mental Capacity Act affects you and how you can plan ahead for when you no longer have the mental capacity to make decisions for yourself. Applies to England and Wales.

About the Mental Capacity Act

• What's the Mental Capacity Act?
• What are my rights under the Mental Capacity Act?
• What's the difference between the Mental Health Act and the Mental Capacity Act?

What's the Mental Capacity Act?

The Mental Capacity Act 2005 is a law that sets out how you'll be supported to make decisions, or how decisions will be made for you. For example, if your ability to make certain decisions is affected by:

• A mental health problem
• An illness
• An injury
• The effects of medication 

The Act tells you:

• What you can do to plan ahead
• How you can ask someone else to make decisions for you
• Who can make decisions for you if you haven't planned ahead

What are my rights under the Mental Capacity Act?

• You have the right to make your own decisions if you have capacity and are aged 16 or over. There are some exceptions. For example, decisions about treatment for mental health problems if you're detained under the Mental Health Act 1983.
• You'll be assumed to have capacity, unless you've had an assessment showing you don't.
• You should receive support to make your own decisions before anyone assumes you don't have capacity, especially from health and social care professionals. You shouldn't be labelled as lacking capacity just because you've made a decision that others don't agree with.
• Any decisions made for you must in your best interests and restrict your freedom as little as possible.

What's the difference between the Mental Health Act and the Mental Capacity Act?

• The Mental Health Act 1983 applies if you have a mental health problem. It sets out your rights if you're sectioned under this Act.
• The Mental Capacity Act applies if you have a mental health problem and you don't have the mental capacity to make certain decisions.

These are the key differences between the Acts:

Mental Health Act 1983

• Applies if you have a mental health problem, such as depression or bipolar disorder.
• You cannot be detained under this Act unless you meet the conditions for sectioning under the Mental Health Act 1983. See our pages on sectioning for more information on when you can be sectioned.
• If you're detained under this Act, the health professionals must follow this Act when making decisions for you. They don't need to follow the best interests checklist in the Mental Capacity Act.
• Applies to treatment you're given for your mental health problems, such as antipsychotic medication. This means you can be given the treatment regardless of whether you agree to it. And regardless of whether you have the mental capacity to agree to it.

Mental Capacity Act 2005

• Applies if you don't have the mental capacity to make a decision that needs to be made. For example, about healthcare or residential care. Health professionals should assess your mental capacity before an important decision can be made on your behalf. But in an emergency, health professionals may need to make a decision for you before they can assess your capacity. 
• Any decisions made about you must follow the best interests checklist in the Act.
• If you cannot be sectioned under the Mental Health Act, you can still be detained and stopped from leaving a place.  This would involve the Deprivation of Liberty Safeguards procedure under the Mental Capacity Act, or by a court order.
• If you don't have capacity to make decisions about treatment, the Act can be used to give you treatment for physical health problems. These may have nothing to do with your mental health problem. If you're not sectioned, treatment for your mental health problem could also be given if you're in hospital and do not object, or haven't refused in the past. Or via an advance decision, attorney or deputy.

This information was published in April 2023. We'll revise it in 2026.

References are available on request. If you would like to reproduce any of this information, see our page on permissions and licensing.