When Decisions Become Difficult: Dementia and Mental Capacity

Woman with light brown skin hugging her partner with dark brown skin, he has a white beard. They are sat on a sofa.

For people living with dementia there may come a time when making decisions become increasingly difficult and a person’s mental capacity needs to be assessed.

This may happen if:

  • the person’s behaviour or circumstances are making those around them doubt whether the person has capacity to make decisions
  • a social worker, GP or other professional may have doubts about the person’s ability to make decisions
  • the person has previously been unable to make a decision for themselves.

By assessing mental capacity, it ensures the person living with dementia can be protected from potential harm and if necessary, support put in place for decisions be made on their behalf. These decisions can range from significant ones such as writing a Will or where to live, to day-to-day decision such as what to wear or what to eat.

Mental Capacity is really just another way of saying a person’s ability to make a decision. It is important that we don’t confuse it with other concepts such as vulnerability or mental ill health because whilst there may be some cross-over between them, it is possible to lack capacity and not be vulnerable or suffering from mental ill-health and vice-versa.


What is the Mental Capacity Act?

The Mental Capacity Act was passed by parliament in 2005 and came into force in 2008. It established 5 core principles and provided a more formal framework for professionals to assess mental capacity. These principles are: the presumption of capacity, supported decision making, unwise decisions, best interests and less restrictive options.

Mental Capacity Assessment

If a person with dementia needs to have a Mental Capacity Assessment, it will involve a 2-stage test and the professional making the assessment will be looking for a range of indicators about their decision-making ability.

The first stage asks 2 questions;

  1. Is there an impairment of, or disturbance in the functioning of, the person’s mind or brain?
  2. Is the impairment or disturbance sufficient that the person lacks the capacity to make the decision in question?

This stage is sometimes called ‘the diagnostic stage’, which I believe is misleading. We are not looking for a diagnosis, rather evidence of an ‘impairment or disturbance’. It is important to remember that diagnosis follow symptoms and so it is the symptoms or presentation of the individual we are looking for rather than the label/diagnosis.

The second stage of the test, sometimes called the functional test, dictates that the person is unable to make a decision if they cannot:

  • understand relevant information about the decision to be made;
  • retain that relevant information in their mind;
  • use or weigh up the relevant information as part of the decision process; or
  • communicate their decision.

If a person lacks capacity in any one of these areas, this represents a lack of capacity (Mental Capacity Act 2005: Code of Practice).

The key here is that the information we are expecting the person to understand, retain, weigh up and use must be relevant. This is why the mini mental state test (can you count backwards from 100 in 7’s? What’s the name of the prime minister?) is not considered to be a test for mental capacity. I don’t know a single decision where being able to count back from 100 in 7’s is relevant. This is often called the threshold of understanding.

The threshold of understanding

The threshold of understanding is, what a person needs to understand to make a specific decision. So for example, what a person needs to understand to decide where to live - is very different to what they need to understand to make a Will.

Caselaw tells us is it is really important that we don’t set the threshold of too high or too low. As a guide we set the threshold of understanding at the level that we would expect the ‘average person on the Clapham omnibus’ to know and understand. As you might expect this often sets understanding lower than you might think – image how much thought the average 18-year-old gives to their use of social media for example!


Capacity is time specific

The final thing to be aware of is that mental capacity is time specific. The Act tells us that a person only has to retain information for the length of the decision process. The question is, how long is the decision-making process?

What this means is we have to identify whether a decision is ‘macro’ or on-going (in which case the person needs to retain information for longer) or whether the decision is ‘micro’ or one-off (in which case they only need to retain the information at that specific moment).

Someone living with dementia may have the capacity to decide what they would like to wear or what they would like to eat for lunch, but they may struggle with managing their finances which involves ongoing and long-term decision making.

If you are concerned about a loved ones’ ability to make decisions, please speak to their GP, social worker, or care providers.

This article is written by Tim Farmer.

He is the Founder of TSF Consultants, Mental Capacity Assessors - https://tsfconsultants.co.uk/

Tim Farmer head shot, he is smiling.

He is a trained mental health nurse with over 25 years of experience of working with adults and children with reduced mental capacity, and he has completed in excess of 3,500 mental capacity tests.