About two million people in England and Wales are thought to lack capacity to make decisions for themselves. They are cared for by around six million people, including a broad range of health and social care staff, plus unpaid carers. Those working in health and social care include: doctors, nurses, dentists, psychologists, occupational therapy, speech and language therapists, social workers, residential and care home managers, care staff (including domiciliary care workers), and support workers (including people who work in supported housing).

Someone’s Mental Capacity, or ability to make a certain decision, may be impacted by:

  • a stroke or brain injury
  • a mental health problem
  • dementia
  • a learning disability
  • confusion, drowsiness or unconsciousness because of an illness of the treatment for it
  • substance misuse.

The Mental Capacity Act 2005

The Mental Capacity Act 2005 (MCA) came into practice in 2007 but is often confused with the Mental Health Act or used to make generalisations about an individual’s ability to understand situations or the actions that they take.

The primary purpose of the MCA is to promote and safeguard decision-making within a legal framework. It does this in two ways:

  • By empowering people to make decisions for themselves wherever possible, and by protecting people who lack capacity by providing a flexible framework that places individuals at the heart of the decision-making process
  • By allowing people to plan ahead for a time in the future when they might lack the capacity.

What is the point of the Act?

The MCA tells us to make sure that decisions are not made for people where they are able to choose for themselves, to help people decide for themselves, even if we do not necessarily agree with the decision.

It protects the rights of a person who may not be able to make a decision where their mind or brain is impacted by illness, disability or the effect of drugs or alcohol, and says that we must take certain steps to make sure that any action that happens is in the best interests of that person.

One part of the Act does relate to the assessment of an individual’s mental capacity in relation to particular decisions, but it is the 5 principles which are the most important to understand first and help you to think about how you might use your knowledge of the MCA in your day to day work:

Five key principles

The Act is underpinned by five key principles (Section 1, MCA). It is useful to consider the principles chronologically: principles 1 to 3 will support the process before or at the point of determining whether someone lacks capacity. Once you’ve decided that capacity is lacking, use principles 4 and 5 to support the decision-making process.

Principle 1: A presumption of capacity

Every adult has the right to make his or her own decisions and must be assumed to have capacity to do so unless it is proved otherwise. This means that you cannot assume that someone cannot make a decision for themselves just because they have a particular medical condition or disability.

Principle 2: Individuals being supported to make their own decisions

A person must be given all practicable help before anyone treats them as not being able to make their own decisions. This means you should make every effort to encourage and support people to make the decision for themselves. If lack of capacity is established, it is still important that you involve the person as far as possible in making decisions.

Principle 3: Unwise decisions

People have the right not to be treated as lacking capacity merely because they make a decision that others deem ‘unwise’. Everyone has their own values, beliefs and preferences which may not be the same as those of other people.

Principle 4: Best interests

Anything done for or on behalf of a person who lacks mental capacity must be done in their best interests.

Principle 5: Less restrictive option

Someone making a decision or acting on behalf of a person who lacks capacity must consider whether it is possible to decide or act in a way that would interfere less with the person’s rights and freedoms of action, or whether there is a need to decide or act at all. Any intervention should be weighed up in the particular circumstances of the case.


Please visit our new page on resources for working with mental capacity