I am frequently asked the question of how and when do family members draw a line in the sand and decide that their elder can no longer take care of themselves. This is a very tough legal and emotional question, probably one of the hardest for family members to address. And where the elder is adamantly uncooperative, it becomes even harder.
No one wants to tell their parent or other loved one that they are no longer capable of taking care of themselves. The emotional confrontation can be devastating and may cause riffs in the family which will never heal. And, it needs to be done.
The legal question is an issue of mental capacity. If your loved one is mentally competent, then they have every right to live however they chose. But at the same time, how they chose to live is often a reflection of their mental capacity. If they insist on living in filth and squalor, this is evidence of their lack of mental capacity to properly provide for their own personal needs.
Each state will have its own laws pertaining to the issue of mental capacity. Normally the issue of mental capacity is a judgment call made by a physician whose evidence is presented to a judge. The judge in turn makes a determination of competency. If someone is found to be incompetent and thus incapable of providing for their own personal needs, the judge will appoint someone to assume that responsibility. From state to state, such a person is referred to variously as a conservator or guardian. The conservator or guardian is delegated the duty to provide (not financially) for the care and needs of the elder. If necessary, it can be done with the assistance of police and/or health care workers.
We all hope for the cooperation of the elder. But when they are uncooperative, it may be necessary to bring a court action to appoint a conservator or guardian for the elder to assure they are protected and receiving good care.