Can Somebody with Dementia or Alzheimer’s Make a Will?
Yes, but there may be a point where this becomes impossible.
Families often face a difficult situation when they receive a Alzheimer’s or dementia diagnosis. Often, the signs preceded the diagnosis. Whether an individual is dealing with a suspicion or “official” diagnosis, there may still be an opportunity to create an estate plan. In fact, there is a great need to do so.
Good News, Estate Planning is Possible
Everybody over the age of 18, even those with a disease affecting their brain, is presumed to be competent to create a will. This means that they have “testamentary capacity”. Even if somebody has been determined by a court to be incompetent, there may be times when the person may have lucid intervals when he knows the extent of his estate and who should receive the inheritance.
Nature of Dementia, Windows of Opportunity
Most of us who have been around suffers of dementia realize that it is not an all or nothing condition. For example, the term “sundowners” 
refers to the worsening of dementia in the late afternoon or evening. At those time, individuals may hallucinate, become agitated or paranoid. See http://sundownerfacts.com/symptoms/ Strangely, for some of these people the conditions disappear or lessen the next morning.
Generally, dementia such as Alzheimer’s is progressive. However, the rate that it progresses varies. According to Alz.org.[i]
The symptoms of Alzheimer’s disease worsen over time, although the rate at which the disease progresses varies. On average, a person with Alzheimer’s lives four to eight years after diagnosis, but can live as long as 20 years, depending on other factors.
From a planning perspective, it is best to draft and sign essential estate and asset planning documents early. These may include:
Powers of Attorney
Wills
Trust
Advanced Healthcare Directives (Living Wills)
HIPAA Releases
Concerns about Long Term Care
In addition, this is an ideal time to make plans for governmental programs that can help pay for care. For example, Medicare does not pay for long-term care in a facility. However, Medicaid can be an option to explore. Also, veterans, their spouses and widows can be eligible for certain pensions such as the VA Wartime Pension also know as Aid and Attendance. However, both Medicaid and certain VA benefits are needs based. This means that those with too much income and or too much in net worth may not be eligible for these programs. However, individuals can become eligible without losing their life savings.
In short, when a diagnosis occurs, it is a good idea to consult with an elder law attorney who has knowledge about the disease, the needs of the family and how to navigate through the Medicaid and VA eligibility requirements. However, failure to take advantage of the opportunity to plan may result in the need of guardianship or other court administered processes.
[i] http://www.alz.org/alzheimers_disease_stages_of_alzheimers.asp