Mental capacity describes a person’s ability to make a specific decision at a specific time. An individual is deemed to lack capacity if, because of an impairment of, or a disturbance in the functioning of the mind or brain, they cannot make a specific decision at the time the decision needs to be made. It does not matter if the impairment or disturbance is temporary or permanent.

The Mental Capacity Act 2005 (MCA 2005) provides a statutory framework to empower and protect adults who are not able to make their own decisions. It does this is by putting the adult at the heart of the decision-making process. It makes clear who can make decisions, in which situations and how they should go about this.

The person who assesses an individual’s capacity to make a decision will usually be the person who is directly concerned with the individual at the time the decision needs to be made. For example, it would be inappropriate for a Psychiatrist to be responsible for the decision as to whether an individual has the capacity to consent to surgery (unless the Psychiatrist was actually making the decision as to whether to carry out the surgery – which is unlikely).


Where the decision relates to making a Safeguarding Concern to the local authority, the assessment should ideally be undertaken by the person raising the concern.

See also:

Mental Capacity Act Code of Practice Guidance

39 Essex Chambers: A Brief Guide to Carrying Out Mental Capacity Assessments