The history and current context of mental capacity legislation and policy

The Five Statutory Principles

The foundation of the MCA is the five statutory principles set out in section 1 of the Act; these principles should govern all decisions regarding care and treatment – in whatever setting and situation:

  • “A person must be assumed to have capacity unless it is established that he lacks capacity” MCA 2005 s 1(2).

    This “assumption of capacity” is partly designed to prevent the use of blanket statements of incapacity linked to someone’s diagnosis. Prior to the Act one often heard statements such as “Mrs Jones has dementia; she does not have capacity”. This statement should never be heard today.

    Because capacity is viewed as time and decision specific before taking any action under the Act, there needs firstly, to be a decision to make and secondly, a trigger which calls the assumption of capacity into question. The trigger may be something said in a conversation or an action taken by the individual but should not simply be the existence of a diagnosis or cognitive impairment.


  • “A person is not to be treated as unable to make a decision unless all practicable steps to help him do so have been taken without success” MCA 2005 s1 (3).

    “Practicable steps” might include interpreters if the assessor does not share the same language as the person, sign language interpreters for the hearing impaired, treatment for acute medical conditions such as antibiotics for infections, having someone to support the individual as part of the process and providing an education programme so that the person can learn new skills.

  • “A person is not to be treated as unable to make a decision merely because he makes an unwise decision” MCA 2005 s 1 (4).

    It is tempting to consider this solely in terms of risky behaviour, but it is more than this. The judge in RB pointed out that someone might understand the risks involved in certain actions and continue to undertake that action regardless. This is not indicative of a lack of capacity.

  • “An act done, or a decision made, under this Act for or on behalf of a person who lacks capacity must be done, or made, in his best interests” MCA 2005 s1 (5).

    There is a checklist in Chapter 5 of the Code of Practice (2007) which assists decision makers to work out what is in someone’s best interests when they can’t make a decision for themselves. Baroness Hale in Aintree University Hospitals NHS Foundation Trust v James [2013] UKSC 67 made it clear that the purpose of best interest is to consider matters from the individual’s point of view rather than the decision makers.

  • “Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be as effectively achieved in a way that is less restrictive of the person’s rights and freedom of action” MCA 2005 s1 (6).

    Any action under the Act has to be proportionate and the decision maker should really clarify all possible alternatives to ensure that the individual’s freedoms are not overly constrained.