Are you mentally capable of signing a will?

How do you tell if someone is mentally capable of signing a will? What does the law say?

There is no one standard test to see if anyone has sufficient mental capacity to sign a will or do anything else. In each case it is a matter of looking at what the person wants to do and then assessing their mental ability to do that act at that time.

There are different causes of incapacity:

  • Mental disorders and illnesses such as schizophrenia and delusional disorder
  • Cognitive disorders such as intellectual disability, brain injury and dementia
  • Fluctuating disorders such as bipolar disorder in which mental incapacity may come and go.

There are different degrees of incapacity. Although the opinion of a doctor or other suitably qualified medical person may be strong evidence of mental capacity, at the end of the day it is a legal question as to whether the person has the ability to act.

Therefore when dealing with capacity to do an act the question must be focussed on that act and not answered in general terms. For example, you should not rely on an opinion, even if given by a doctor, which says “This person lacks the mental capacity to handle their affairs” as that is not specific enough.

In order for someone to have the mental capacity to sign a will the following questions must be asked:

  • Do they know that they are making a will and what the legal effect of making a will is?
  • Do they know what property they have to deal with?
  • Do they know what moral claims should be taken into account when deciding what to say in their will?

In order to form an opinion on these things the professional giving the opinion has to be able to discuss these matters with the person. For example, in order for a doctor to give an opinion on the person’s understanding about the second bullet point above, the doctor would have to know what property the person has. Otherwise the doctor has no way of knowing whether the person understands what he or she is doing.

So, if you’re going to get a medical opinion on mental capacity you have to make sure that the person who is giving the opinion has all the information to enable him or her to answer the questions above.

The trouble with not doing it right first time is that the act of signing a will is only likely to be challenged after the person has died and is no longer able to appear as a witness.

If there is any doubt about mental capacity, it is important to get an opinion from at least one person who specialises in this sort of medicine and in doing that, to give them full information so that they are able to form a reliable opinion that will stand up in court at a later date.

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