Mental capacity

'Mental capacity' means being able to make your own decisions.

Someone lacking capacity - because of an illness or disability such as a mental health problem, dementia or a learning disability - cannot do one or more of the following four things:

  • Understand information given to them about a particular decision
  • Retain that information long enough to be able to make the decision
  • Weigh up the information available to make the decision
  • Communicate their decision.

We all make decisions, big and small, every day of our lives and most of us are able to make these decisions for ourselves, although we may seek information, advice or support for the more serious or complex ones. For large numbers of people their capacity to make certain decisions about their life is affected either on a temporary or on a permanent basis.

  • A person with a learning disability may lack the capacity to make major decisions, but this does not necessarily mean that they cannot decide what to eat, wear and do each day.
  • A person with mental health problems may be unable to make decisions when they are unwell, but able to make them when they are well.
  • A person with dementia is likely to lose the ability to make decisions as the dementia gets more severe.

What causes a lack of mental capacity?

A lack of mental capacity could be due to:

The Mental Capacity Act 2005

Many people provide health treatment or social care support to people who may have difficulties making some or all decisions about their lives. If the person is aged over 16 years and living in England or Wales, then the Mental Capacity Act applies to how professionals and other paid carers work with them (Scotland has its own law, the Adults with Incapacity (Scotland) Act 2000). Specifically they must follow the guidance set out in the Act's Code of Practice unless there is a good reason for not doing so.

The Mental Capacity Act aims to empower and protect people who may not be able to make some decisions for themselves. It also enables people to plan ahead in case they are unable to make important decisions for themselves in the future.

The Act can apply to all sorts of decision such as:

  • major decisions such as decisions about personal finance, social care or medical treatment
  • everyday decisions such as decisions about what to wear or eat

The law works on the principle that everyone is assumed to have capacity to make decisions for themselves if they are given enough information, support and time. It protects their right to make their own decisions and to be involved in any decisions that affect them. A person's capacity must be judged according to the specific decision that need to be made, and not solely because of their illness, disability, age, appearance or behaviour  An important principle in the law is that just because someone is making what seems to be an unwise decision (even if they have an illness or disability) this does not necessarily mean they lack capacity. There are legal safeguards that must be followed when making a decision on behalf of some who lacks the capacity to make the decision - it must be done in their 'best interest'.

Find out more about the Mental Capacity Act

Mental capacity and the Mental Health Foundation

We are recognised as a leading expert on all aspects of mental capacity and are unique because our work focuses on the three main groups of people affected by mental capacity issues:

Since 2006 we have successfully carried out a number of projects on mental capacity issues as well as doing extensive policy and public affairs work in the field. We are seen as being the leading third sector organisation with expertise in the mental capacity field from the perspective of many key policy makers, health and social care services, other third sector organisations, the media and other stakeholder organisations.

Best Interests Decision Making

We were a research partner on a major study of the Mental Capacity Act led by the Norah Fry Research Centre at the University of Bristol and also involved the University of Bradford. The study looked at best interests decisions made under the Act and its final report found that there was a lot of good practice but some health and social care staff still need to be more aware of how to apply the Mental Capacity Act.