My sister has become progressively mentally ill during the last 2 years. She has a thyroid problem and has not taken her medication for about 2-3 years. This all began with a period of severe depression after a break up. She seems to be bipolar - but I believe her behavior is more schizophrenic...she believes that people are using her identity - has attempted reporting this to the police and has also called Social Security. She continuously says that they're out to get her. She currently lives with my "Senior" parents. She does not leave the house. She says that "they" will kill her. My question is....Is there anything that can be done to "force" someone to get help/treatment? All my siblings have tried talking and reasoning with her, but she's now managed to frustrate everyone....constant arguments. She insists that we're the stupid ones. "They're" going to get us. Are there any options besides her initiating the treatment? My parents don't deserve this at this point in their lives.
Buy the book, I Am Not Sick, I Don't Need Help by Dr. Xavier Amador who used its techniques to get his brother Henry to take the meds even though Henry was in denial he had a problem. Denial, or anosognosia, the lack of awareness that one is ill, is actually a symptom.
That is why your family's persistent attempts to "reason" or present "logic" to your sister have fallen on deaf ears. Before they try the same tactics over and over with no success, I urge you to read Amador's book, and proceed to the section where it talks about how to couch what you say in terms that will convince the loved one to take the meds.
It appears you sister might be suffering from anosognosia. Read the book. You it to yourself and your family to get some peace in your life. If your sister becomes a danger to herself or others, or if you can convince a judge or admitting psychiatrist that she is this danger, then she can be forced into treatment.
Until then, know that you are not alone and a lot of people go through this. I've read the Amador book, and others can also vouch for its techniques.
As usual Christina's answer is very helpful. I thought I'd enclose a link to a particularly helpful site where the answer to your question is discussed in even more detail.
As a caveat, I'm a Behavioral Scientist with a son who has been terribly ill for several years with one of the many forms of Schizophrenia. My son has absolutely no awareness of his illness and in fact uses much of the professional jargon that he learned while growing up at home to convince/confuse doctors and judges that he is entirely healthy despite behavioral manifestations to the contrary. His ability to do that supposedly 'protects' him under HIPPA to remain in a state of continuous illness and his family in a continuous state of despair.