Mental Capacity – Part 2

Guest Blog_ Mental capcity (1)

This article is the second of two on mental capacity. This article looks at how mental capacity is assessed and the decision-making process. The first article considered what mental capacity is and the key principles that underpin it.

How is mental capacity assessed?

There is a two-stage test of capacity which is set out in the Mental Capacity Act (MCA) 2005.

  1. Is there an impairment of or disturbance in the functioning of a person’s mind or brain? If so:
  2. Is the impairment or disturbance sufficient that the person lacks the capacity to make a certain decision?

The MCA says a person is unable to make a decision if they cannot do one or more of the following:

  • Understand information given to them that is relevant to the decision they want to make.
  • Retain that information long enough to be able to make the decision.
  • Weigh up information available to make the decision.
  • Communicate their decision by any means possible (verbal and nonverbal).

What is the decision-making process?

Before deciding that someone lacks capacity to make a particular decision, it is important to take all practical and appropriate steps to enable the person to make the decision for themselves. These steps must be taken in a way which reflects the person’s individual circumstances and their particular needs. For example, what is the best way of presenting information to a person? Perhaps they respond better to something more visual like photographs and drawings? Would an interpreter assist a person’s ability to communicate?

Another consideration might be, is there a particular time of day when the person understands better? Some people aren’t morning people so perhaps a discussion would work better and be more effective later in the day? If a person is unwell, would medical treatment improve their decision-making abilities?

If someone lacks the capacity to make a decision and the decision needs to be made for them, the MCA states the decision must be made in their best interests. It should never be made in the best interests of the person making the decision.

The MCA provides a non-exhaustive checklist to consider when deciding what is in a person’s best interests.

Its important to note that whilst the MCA covers a wide range of decisions, there are certain decisions which can never be made on behalf of a person who lacks capacity. These excluded decisions include decisions relating to family relationships and mental health and are set out in the MCA.

How can we help?

If someone lacks capacity having not made an Enduring Power of Attorney or a Lasting Power of Attorney, then an application can be made to the Court of Protection for the appointment of a Deputy. The Court of Protection oversees the operation of the MCA.

Our specialist Court of Protection team has a wealth of experience. If you have any questions or queries, then please contact the writer Charlene Hughes by email at

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