In legal terms, mental capacity is defined by the ability to make your own decisions. In order to demonstrate mental capacity, an individual needs to be able to do the following:

• Understand information given to them about a particular decision
• Retain the information long enough to be able to make an informed choice
• Properly evaluate the data and respond to it accordingly
• Communicate the decision they have made to the relevant parties

Traumatic injuries, strokes, dementia, severe learning disabilities or severe mental health problems can all affect a person’s mental capacity in ways that are temporary or permanent. Some people will be able to make decisions on certain days, and not on others; in other cases, the individual may be at risk of gradually losing their mental capacity as their condition grows more severe.

For help determining whether you, a family member or loved one has or could lose the capacity to make important life decisions, take a look at our Mental Capacity Act Quiz.

The Mental Capacity Act, passed in 2005, is the law that applies in England and Wales to protect individuals aged 16 and over who are unable to make decisions for themselves, as well as to help people plan against a potential loss of mental capacity in the future.

The act applies to major decisions about personal finance and health and social care, as well as everyday decisions about what to wear or eat. It protects everyone’s right to make their own choices and be involved in any decisions that affect them, while putting in place legal safeguards to ensure that any decision taken on another person’s behalf is in their best interest.

The Mental Capacity Act advises:

• Not to treat someone as lacking the capacity to make a decision because they have made an unwise decision
• To assume someone has the capacity to make a decision on their own unless that’s proved otherwise
• Help people make their own decisions where possible
• Make sure decisions made on behalf of someone without capacity are in their best interests
• Before making a decision on behalf of someone who lacks capacity, always question if there is something else that can be done that would interfere less with their basic rights and freedoms

The Mental Capacity Act states that a two-stage process should be undertaken when assessing an individual’s capacity. 

• Stage 1: Also known as ‘the functional test’, this part of the assessment asks investigates whether the person is unable to make a particular decision
• Stage 2: This stage focuses on why the person is unable to make a decision - is it because of an impairment of their brain or due to external factors such as alcohol or drug use?

The law does not restrict who can carry out a mental capacity assessment, however, the following types of professionals typically are more likely to have the skills required to carry out effective assessments:

• Doctors
• Solicitors
• Psychologists
• Psychiatrists
• Social workers

Doctors and lawyers are both able to provide mental capacity assessments when it is suspected that an individual no longer possesses the capacity to make educated decisions in their own best interest.

These assessments need to go beyond the age and appearance of the person in question or any assumptions about their condition or behaviour; distinctions should also be made between a person making informed choices that others may not agree with, and someone who has genuinely lost mental capacity.

Mental capacity often needs to be assessed regularly, particularly when a care plan is being developed or reviewed on their behalf.