What is Mental Capacity?

Mental Capacity refers to an individual's ability to make a specific decision at a particular time. To be considered as having mental capacity, a person must be able to:

• Understand the relevant information related to the decision.
• Retain that information long enough to consider it.
• Evaluate the available options and understand the possible outcomes.
• Communicate their decision by any means – verbally, in writing, or through gestures or other forms of expression.

Mental capacity is assessed on a decision-by-decision basis, meaning it is not a general or fixed trait.

An individual may have the capacity to make certain decisions, such as those related to daily activities, while lacking the capacity for more complex decisions, such as those involving medical treatment or financial matters.

Capacity can also fluctuate over time and may be influenced by factors such as illness, medication, or emotional distress.

Some individuals may need extra support or resources put in place to exercise their own decision-making.

Importantly, the law operates on the principle of presumed capacity — every adult (aged 16 years and over) is assumed to have the ability to make their own decisions, unless there is clear and specific evidence to the contrary.

The starting point for the researcher is that all adults are presumed to have capacity.

Mental Capacity and Research

• A person’s decision is viewed as their own.
• Some adults may lack capacity and may have communication difficulties that affect their ability to:
  • Understand relevant information about a study
  • Retain that information
  • Weigh up what that information means to them
  • Communicate a decision about whether to participate or not
• Of these adults with difficulties, some may be able to exercise their own decision-making if they are provided with relevant adjustments and supports. For others, provision of relevant adjustments and supports will allow them to engage in the decision-making process with a consultee.

Capacity and The Law

Autonomy

Formal recognition of people’s interest in:

• Making decisions
• Acting voluntarily

Research Value

The research is of value to the person. It brings knowledge about the:

• Cause
• Treatment
• Care of others with the same or similar condition

Protection

The individual should not be exposed to experiences that:

• Restrict their usual lives
• Exploit them as individuals
• Trigger a negative response

Understanding Risk, Best Interest Decisions, and Mental Capacity

Please watch the following video on understanding risk, best interest decisions, and mental capacity: