How is a person’s mental capacity and decision making assessed?

The Mental Capacity Act 2005 states that ‘all practicable steps must be taken to help’ a person to make the decision for themselves, and for these to be unsuccessful, before it’s decided that a person lacks capacity for a particular decision. 

There are many areas of decision making in relation to which capacity can be assessed. Some examples include:

• Capacity to make decisions about where a person should live and receive care and support
• Capacity to manage one’s own property and financial affairs
• Capacity to make a will
• Capacity to make a lasting power of attorney
• Capacity to conduct court proceedings
• Capacity to make decisions about who to have contact with
• Capacity to engage in sexual relations with others

It is therefore possible for an individual to have capacity in regard to one aspect, for example  making a will, but to lack capacity for another, such as conducting their own property and financial affairs.

Furthermore, if a person does lack capacity in a certain area, this is not necessarily permanent in all cases. An individual can have capacity for a short period of time, during which they are capable of making the decision in question, despite later losing this capacity and becoming unable to make the same decision. This is called fluctuating capacity and a lasting power of attorney may help in this situation. Capacity can therefore be temporary in some cases, although this very much depends on the individual. Temporary capacity can be the result of a variety of factors, often caused by certain types of medical conditions such as acute confusion or delirium and the effects of excess alcohol.

Although it is common to assume that your loved one lacks capacity when they make ‘out of character’ or unwise decisions, especially when these are made toward the end of their lifetime, the law provides that a person should not be treated as unable to make a decision merely because they make an unwise decision. 

The question in relation to an individual’s capacity is therefore a complicated one, for which there is no ‘one size fits all’ answer. It is hugely dependant on the specific circumstances of the individual and the matter being disputed. Therefore, unless an individual has been assessed by a professional as lacking capacity, there is no reliable way of determining whether they in fact do lack capacity.