Robin Williams had Lewy body dementia, not Alzheimer's
Robin Williams died by suicide in August 2014. His wife Susan disclosed after his death that he had been diagnosed with Lewy body dementia, a progressive brain disease that affects movement, thinking, and mood. Williams had not publicly announced the diagnosis before his death, and his family revealed it only during the medical examiner's investigation.
Lewy body dementia is caused by abnormal protein deposits called Lewy bodies that build up inside nerve cells in the brain. These deposits damage the cells that control movement, memory, and emotional regulation. It is the second most common type of dementia after Alzheimer's disease, but it is often misdiagnosed as Parkinson's disease, depression, or other conditions because the symptoms overlap with so many illnesses.
Williams had experienced symptoms consistent with Lewy body dementia in the months before his death, including tremors, stiffness, and difficulty with balance — physical signs that are hallmarks of this particular form of dementia. His family later described his struggle with the diagnosis as a major factor in his final decision.
Key Takeaways
- Robin Williams was diagnosed with Lewy body dementia, which causes movement problems, memory loss, and mood changes, and is often mistaken for Parkinson's disease.
- Lewy body dementia accounts for 5 to 10 percent of all dementia cases and progresses differently than Alzheimer's, with physical symptoms often appearing first.
- The disease can cause hallucinations, severe depression, and rapid changes in alertness that make it particularly difficult to live with and treat.
- Williams' case drew public attention to a form of dementia that is frequently misdiagnosed, leading to delayed treatment and incorrect medication.
How Lewy body dementia differs from other forms
Lewy body dementia produces a different pattern of symptoms than Alzheimer's disease. In Alzheimer's, memory loss usually comes first and is the most obvious early sign. In Lewy body dementia, movement problems — tremor, rigidity, slow movement, or balance trouble — often appear before memory loss becomes severe. This is why the disease is sometimes confused with Parkinson's disease, which also causes these physical symptoms.
Another key difference is that Lewy body dementia frequently causes vivid hallucinations early on. People may see people, animals, or objects that are not there, and these hallucinations feel completely real. Alzheimer's patients may become confused, but hallucinations are less common and usually come later. Lewy body dementia also causes extreme fluctuations in alertness and attention — a person may be sharp one hour and confused the next, sometimes within minutes.
The disease also tends to cause severe depression and anxiety, along with sleep disturbances. People with Lewy body dementia often experience REM sleep behavior disorder, in which they act out their dreams physically. These mood and sleep changes can be as disabling as the memory loss itself.
Why Lewy body dementia is often missed or misdiagnosed
Doctors frequently misdiagnose Lewy body dementia as Parkinson's disease, depression, or psychiatric illness because the early symptoms overlap so much. A person with tremor and stiffness may be sent to a neurologist for Parkinson's testing. A person with severe depression and hallucinations may be referred to psychiatry. By the time the pattern becomes clear, the disease has often progressed significantly.
Another reason for misdiagnosis is that Lewy body dementia does not show up clearly on standard brain imaging. An MRI or CT scan may look relatively normal even when the disease is advanced. Alzheimer's disease can sometimes be detected through imaging or cerebrospinal fluid tests, but Lewy body dementia usually requires a clinical diagnosis based on the pattern of symptoms over time. A definitive diagnosis often comes only after death, during autopsy, when Lewy bodies can be seen under a microscope.
Because the disease is less well-known than Alzheimer's, many primary care doctors and even some specialists do not think to look for it. This means people may receive treatment for the wrong condition — for example, antipsychotic medications that can actually make Lewy body dementia worse rather than better.
What Williams' case revealed about living with the disease
After Williams' death, his wife and neurologists who had treated him described the profound difficulty of living with Lewy body dementia. The combination of physical decline, cognitive changes, hallucinations, and severe depression created a situation that felt hopeless to him. Unlike some forms of dementia that progress slowly over many years, Lewy body dementia can move quickly and unpredictably.
Williams' case brought attention to the fact that dementia is not only a memory disease. The emotional and psychological toll — the loss of control, the frightening hallucinations, the inability to trust one's own mind — can be as devastating as the cognitive decline. His death sparked conversations among neurologists and mental health professionals about how to better support people with Lewy body dementia and how to recognize when someone is in crisis.
The case also highlighted that people with dementia remain aware of their diagnosis and its progression, at least in the early and middle stages. Williams understood what was happening to him, and that awareness, combined with the severity of his symptoms, contributed to his despair.
Current treatment and support for Lewy body dementia
There is no cure for Lewy body dementia, but medications can manage some symptoms. Cholinesterase inhibitors — drugs like donepezil — may help with memory and thinking. Carbidopa-levodopa can help with movement problems. However, antipsychotic medications, which are sometimes used for hallucinations in Alzheimer's patients, can be dangerous in Lewy body dementia and may worsen symptoms or cause severe side effects.
Treatment focuses on managing individual symptoms and supporting the person's quality of life. This includes physical therapy for movement problems, speech therapy if swallowing becomes difficult, and mental health support for depression and anxiety. Sleep hygiene and structured routines can help with the fluctuations in alertness and the sleep disturbances that are common in this disease.
Family support and caregiver education are critical. Caregivers need to understand that the hallucinations are real to the person experiencing them, that mood swings are part of the disease and not personal rejection, and that the person's abilities may change dramatically from day to day. Support groups specifically for Lewy body dementia exist through organizations like the Lewy Body Dementia Association, which provides resources for both patients and families.
How to recognize Lewy body dementia symptoms
The early signs of Lewy body dementia include tremor or stiffness, slow movement, balance problems, and difficulty with coordination. These physical symptoms may appear before memory problems become obvious. Vivid hallucinations — often of people or animals — are another early warning sign, particularly if they occur without the person being confused about other things.
Fluctuating alertness is a hallmark of the disease. A person may be clear and engaged in the morning, then confused and drowsy by afternoon, then sharp again at dinner. This pattern is different from the more steady decline seen in Alzheimer's. Severe depression, anxiety, and sleep problems, especially acting out dreams, are also common early signs.
If you or a family member experience this combination of symptoms — physical movement problems, hallucinations, and fluctuating thinking — it is important to see a neurologist who is familiar with Lewy body dementia. Many primary care doctors will not recognize the pattern, so asking specifically about Lewy body dementia or requesting a neurology referral can help may support an accurate diagnosis.
Frequently Asked Questions
Is Lewy body dementia hereditary?
Lewy body dementia is not usually inherited. Most cases appear to be sporadic, meaning they occur randomly without a family history. However, researchers have identified some genetic variations that may increase risk, and a small number of families have shown patterns of inheritance. If dementia runs in your family, mention this to your doctor, but most people with Lewy body dementia have no family history of the disease.
How fast does Lewy body dementia progress?
The progression varies widely. Some people decline over 5 to 8 years, while others progress more slowly or more quickly. The disease is unpredictable — a person may be stable for months, then decline rapidly. This unpredictability is one reason the disease is so difficult to live with and why planning ahead is important for both the person and their family.
Can Lewy body dementia be prevented?
There is no known way to prevent Lewy body dementia. Researchers are studying whether cardiovascular health, cognitive activity, and other lifestyle factors might reduce risk, but no prevention strategy has been proven. The focus is currently on early recognition and symptom management rather than prevention.
Why did antipsychotic drugs make Williams' symptoms worse?
Antipsychotic medications can cause severe adverse reactions in people with Lewy body dementia, including increased confusion, rigidity, fever, and in some cases life-threatening complications. These drugs work differently in Lewy body dementia than in other conditions, and doctors now know to avoid them in this population. This is one reason accurate diagnosis is so important.
Where can I find a doctor who specializes in Lewy body dementia?
The Lewy Body Dementia Association maintains a directory of specialists and support resources. Your primary care doctor can also refer you to a neurologist, and you can ask specifically whether they have experience diagnosing and treating Lewy body dementia. Academic medical centers and memory care clinics are more likely to have specialists familiar with this disease.