The Mental Capacity Act (MCA) is designed to protect and empower people who may lack the mental capacity to make their own decisions about their care and treatment. It applies to people aged 16 and over. It covers decisions about day-to-day things like what to wear or what to buy for the weekly shop, or serious life-changing decisions like whether to move into a care home or have major surgery. Someone can lack capacity to make some decisions (for example, to decide on complex financial issues) but still have the capacity to make other decisions (for example, to decide what items to buy at the local shop).

A mental capacity assessment is required mostly when it is evident that a person doesn’t have the mental capacity to make decisions when needed. The evidence may be available in the form of an impairment or disturbance in the brain, which would be the reason behind the person not being able to make the decision. Under the MCA, you are required to make an assessment of capacity before carrying out any care or treatment if you have reasonable belief someone lacks capacity – the more serious the decision, the more formal the assessment of capacity needs to be.

What Is The Test For Assessing The Mental Capacity Of A Person?

There are two stages in the test of capacity:

1. Diagnostic Test

2. Functional Test

Stage one is the Diagnostic Test:

Is there an impairment of, or disturbance in, the functioning of the person`s mind or brain and is that impairment or disturbance sufficient to cause the person to be unable to make that particular decision. This can be a confirmed diagnosis or signs and symptoms to indicate a diagnosis. Examples of an impairment or disturbance include: Brain Injury, Dementia, Physical or Medical conditions that cause confusion, drowsiness, or loss of consciousness etc. Furthermore, it must be seen whether the impairment or disturbance is of a temporary or permanent nature. But just because a person has one of these health conditions does not necessarily mean they lack the capacity to make a specific decision.

Stage two would normally only progress if the criteria in stage one is met, although there may be other behavioural reasons to assess capacity at the onset.

Stage two is the four step Functional Test:

The second test known as the ‘functional test’ is linked with the first test. When it becomes apparent that the person is suffering from impairment, at this stage it is determined whether or not that impairment has stopped the person from making a decision at a specific time. This is a functional test focusing on how the decision is made, rather than the outcome or the consequence of the decision.

  • To understand the information relevant to the decision, 
  • To retain that information, 
  • To weigh that information as a part of the process of making a decision, 
  • To communicate his/her decision (whether by talking, using sign language or any other means).

Mental Capacity Act 2005

The Mental Capacity Act 2005 summary  provides information on the Act and how it is underpinned by a set of five key principles. It makes it clear who can take decisions, in which situations, and how they should go about this. It provides information which helps people to plan ahead for a time when they may lose capacity.