Legal validity of a signature from someone with a mental illness

Hi everyone,

I was wondering if anyone could point me in the right direction regarding how to get
official confirmation that someone is mentally competent—meaning their signature
is legally binding on formal documents (specifically, a life estate agreement). This person doesn't have a legal guardian at the moment; they’re already making their own medical decisions and signing off on things at the hospital.

Thanks so much for any help you can give.

The bottom line:
An individual doesn't lose their legal capacity just because they're struggling; only a court can actually strip that away. This happens through a formal legal proceeding involving medical evaluations. If the judge determines the person truly lacks the ability to make independent decisions, they’ll issue a ruling to revoke their capacity, at which point the Department of Social Services steps in to appoint a legal guardian.
Until that official ruling is made, the person remains legally empowered to enter into contracts and conduct business. However, there is a significant caveat: if someone enters into an agreement while they are mentally incapable of understanding what they are doing—even if they haven't been formally declared incompetent yet—that transaction is considered void. This can be challenged and proven in court later on.
If you have genuine concerns that someone isn't capable of looking after their own interests, I suggest taking action to protect them. You should reach out to the Department of Social Services or consult with an attorney who can initiate the necessary proceedings to address their legal capacity.

Don’t act too surprised when the court eventually decides that this mentally ill individual is perfectly capable of making their own life choices, because let's be honest, not everyone struggling with mental health issues is incapable of basic reasoning. Some people might be out of touch, sure, but there are plenty who are actually quite brilliant in every sense of the word.