Mental Capacity Assessments

The Mental Capacity Act states that a person lacks capacity if they are unable to make a specific decision, at a specific time, because of an impairment of, or disturbance, in the functioning of mind or brain. 

Mental capacity is the ability to make a decision. If a person lacks capacity, they have an impairment or disturbance that leaves them unable to make a decision. The loss of capacity could be partial or temporary. It is possible for a person to lack capacity to make one specific decision but not about another.


Assessing Mental Capacity

An assessment that a person lacks the capacity to make decisions should never be based simply on the person’s age, appearance, assumptions about their condition (includes physical disabilities, learning difficulties and temporary conditions (eg, drunken-ness or unconsciousness), or any aspect of their behaviour.

Assessing a person’s capacity accurately is important; otherwise, a person might be denied the right to make a decision because it is unwise and not in their best interests.

The starting assumption should always be that the person has capacity. The Act details a two-stage test of capacity:

  • Does the person have an impairment, or a disturbance in the functioning, of their mind or brain?

  • Does the impairment or disturbance mean that the person is unable to make a specific decision when they need to?


Functional tests of capacity

To be able to make a decision a person should be able to:

1.    Understand the decision to be made and the information provided about the decision. The consequences of making a decision must be included in the information given.

2.    Retain the information – a person should be able to retain the information given for long enough to make the decision. If information can only be retained for short periods of time, it should not automatically be assumed that the person lacks capacity. Notebooks, for example, could be used to record information which may help a person to retain it.

3.    Use that information in making the decision – a person should be able to weigh up the pros and cons of making the decision.

4.    Communicate their decision – if a person cannot communicate their decision – for example, if they are in a coma – the Act specifies that they should be treated as if they lack capacity. You should make all efforts to help the person communicate their decision before deciding they cannot.