What is the meaning of mental capacity


Mental capacity 

Mental capacity is normally defined by a person’s ability to make decisions for themselves, at the time a decision needs to be made. Mental incapacity, where a person is unable to make decisions for themselves, can be due to several reasons and include those with:

  • dementia
  • a severe learning disability
  • a brain injury
  • a mental health illness
  • a stroke
  • unconsciousness caused by an anaesthetic or sudden accident

However, just because a person has one of these health conditions does not always mean they lack the mental capacity to make a specific decision for themselves. It could be that whilst they lack the capacity to make more complex decisions (for example, regarding financial issues) they still can have the capacity to make other decisions (for example, how to dress and make general day to day decisions)

Mental incapacity, where you lack capacity to make a decision, is normally defined if you are unable to:

  • understand information given to you relevant to the decision
  • retain the information given to you for long enough to be able to make the required decision
  • use or weigh up all your options before making your decision; and/or
  • to communicate your decision (whether by talking, using sign language or any other means).

If you lose mental capacity the Mental Capacity Act 2005 (MCA) is there to protect you and your rights.

What is the Mental Capacity Act?

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.

MCA can cover decisions about day-to-day things like what to wear or what to buy for the weekly shop; or it can also cover more serious life-changing decisions like whether there is a need to move into a care home or decisions regarding major surgery for example.

Anyone who makes decisions on behalf of another individual must follow the five key principles of the Mental Capacity Act. These five principles are:

  • Presumption of capacity
  • Support to make a decision
  • Ability to make unwise decisions
  • Best interest
  • Least restrictive

The principles under 4 and 5 only apply when a person has been assessed to not have the mental capacity regarding the decision in question. Whilst it is not a principle of the Act, it is key to remember that mental capacity is time and decision specific.

Anyone who has the responsibility to make decisions on behalf of someone else must also follow the Mental Capacity Act Code of Practice and only make decisions that are in their best interests. Furthermore, before someone can make decisions on behalf of an incapacitated individual, they should undertake a comprehensive mental capacity assessment.

Court of Protection and Mental Capacity Law

The Court of Protection is responsible for assisting people that no longer have the mental capacity to make decisions. They are responsible for:

  • deciding whether someone has the mental capacity to make a particular decision for themselves
  • appointing deputies to make ongoing decisions for people who lack mental capacity
  • giving people permission to make one-off decisions on behalf of someone else who lacks mental capacity
  • handling urgent or emergency applications where a decision must be made on behalf of someone else without delay
  • making decisions about a lasting power of attorney or enduring power of attorney and considering any objections to their registration
  • considering applications to make statutory wills or gifts
  • making decisions about when someone can be deprived of their liberty under the Mental Capacity Act

Applying to the Court of Protection is quite a complex process that requires specialist legal advice and can take time to arrange. – Find out more about our Court of Protection services

Planning for the future

If you are worried that you or a loved one might lose mental capacity in the future, there are things that you can do in preparation, including considering the following documents:

Lasting Power of Attorney - An LPA means that you give a trusted person or people the power to make decisions for you if you lose the ability to decide for yourself.  – find out more about our Lasting Powers of Attorney services or read our blog about

There are two different types of LPA.

Property and financial decisions

Health and welfare decisions

  • Make an advance statement – this is not legally binding; however, medical professionals should still make practical effort to follow your wishes. It is a general preference about your treatment and care, and you can make an advance statement if you have mental capacity at the time.
  • Make an advance decision - this is legally binding; and It gives you the legal right to refuse specific medical treatment in future when you may not have the mental capacity to make the decision for yourself at that time. An advanced decision cannot be used for anything else.

Mental Capacity and Court of Protection Solicitors

This area of law can often be complex and unfortunately, it is not uncommon for disputes to arise regarding the handling of a loved one’s affairs when the loss of capacity occurs. Without appropriate legal advice, problems and disputes can arise during the capacity assessment process which can result in decisions being made by health and social services rather than by the individual or by a loved one or family member.

At Russell & Russell our specialist mental capacity and court of protection solicitors have the knowledge and expertise to provide expert advice on the Mental Capacity Act 2005. We can advise on all stages of the assessment process, make applications to the Court of Protection or provide guidance on the appropriate solution should disputes arise.

To find out more about the Mental Capacity Act, making applications to the Court of Protection or any other matters discussed in this article, you can speak to our expert private client solicitors who will be able to guide you through the process and discuss the most appropriate solution for you and your circumstances. Call 0800 103 2600 or make an online enquiry. For emergencies, you can contact us via our Wills & Probate 24 hour help line on 07919 591416

Please note that this article is meant as general guidance and not intended as legal or professional advice. Updates to the law may have changed since this article was published


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