This is not a medical blog, but medicine and the law interact extensively when it comes to determining (or challenging) a person’s legal capacity.  To prove lack of capacity requires evidence of a mental defect, such as dementia or Alzheimer’s disease.  Alzheimer’s also plays a role in proving a weakness of mind—required for undue influence.

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The problem is that dementia and Alzheimer’s is often overlooked, misdiagnosed, or not diagnosed at all even though the conditions may be present.  For example, Alzheimer’s patients can go ten to fifteen years with the disease before showing any outward symptoms.  In part, a lack of diagnoses stems from the difficulty medical science has had determining when a person has Alzheimer’s disease.

In a recent report by CNN, as reported by Dr. Sanjay Gupta, detecting the presence of Alzheimer’s disease may be possible by looking into a person’s eyes.  Dr. Gupta explains that Alzheimer’s can be detected by sticky plagues in the brain made up of proteins called “beta amyloid.”  But these proteins are very difficult to detect in the brain without doing invasive surgery.  However, researchers now believe that the same proteins found in the brains of Alzhemer’s patients may also be present in the eyes—at the back of the retina.  They are now conducting a clinical trial to see if the eye test can identify patients who are starting to develop Alzheimer’s disease.

Better diagnoses means better understanding of the disease, and a chance to address the problem before it progresses.  For the legal community, earlier diagnosis provides a better (and more accurate) idea of when an elder becomes incapacitated or susceptible to undue influence because of a weakness of mind. 


In California, proving a weakness of mind or lack of capacity requires medical evidence of a mental defect (see Probate Code Section 811).  We have come across many elders who are obviously susceptible to undue influence, yet they have no medical diagnosis of a mental defect.  As a result, their mental condition cannot be established in a Court proceeding.  By having a more accurate picture of a person’s mental capacity, the true state of their decision making abilities can be determined.  This can be a huge breakthrough to protecting elders and ensuring their true desires are reflected in their Trusts and Wills.

They say the eyes are the window to the soul, but they may also be the window to better mental health too.

(For more on signs of Alzheimer’s, see this CNN article: The 10 warning signs of Alzheimer’s.)