Mental Capacity Act 2005

A general guide on 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 is the Mental Capacity Act?

If you can’t make decisions for yourself because you don’t have the mental capacity to make them, the Mental Capacity Act 2005 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.

The Mental Capacity Act will be important to you if you think that your ability to make certain decisions will be affected in the future because of your mental health problem, an illness, an injury, or outside reasons like the effect of medication you are prescribed.

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 18 or over. There are a few exceptions, such as decisions about treatment for mental health problems if you are detained under the Mental Health Act 1983.
  • You will be assumed to have capacity, unless you have 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 is the difference between the Mental Health Act and the Mental Capacity Act?

This table compares the differences between the Acts:

Mental Health Act 1983

Mental Capacity Act 2005

  • Applies if you have a mental disorder, such as depression or bipolar disorder.
  • If you are detained under this Act, the health professionals must follow this Act when making decisions for you. They do not need to follow the best interests checklist in the Mental Capacity Act.
  • Applies to treatment you are 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.
  • Applies if you do not have the mental capacity to make a decision that needs to be made, for example about healthcare or residential care.

    Usually the health professionals should carry out a mental capacity assessment of you before an important decision can be made on your behalf, although in an emergency, this might happen before the assessment is done.
  • If you cannot be sectioned under the Mental Health Act, you can still be detained and stopped from leaving a place using the Deprivation of Liberty Safeguards procedure under this Act or by a court order.
  • Can be used to give you treatment for physical health problems that have nothing to do with your mental health problem if you don't have capacity to decide whether to have the treatment. If you are not sectioned, treatment for your mental health problem could also be given, if you are in hospital and do not object or have not refused in the past or via an advance decision, attorney or deputy.


This information was published in November 2017. We will revise it in 2019.

Mental Health A-Z

Information and advice on a huge range of mental health topics

> Read our A-Z


Helping you to better understand and support people with mental health problems

> Find out more

Special offers

Check out our promotional offers on print and digital booklets, for a limited time only

> Visit our shop today