
When Jackie Bezos, Amazon founder Jeff Bezos’ mom, died in 2025, her death helped increase public awareness of a specific type of dementia. Called Lewy body dementia, it’s a disease that progressively leads to the degeneration of many parts of the brain over time.
The underlying cause of Lewy body dementia is connected to the distribution of proteins called Lewy bodies throughout the cells in the brain. As these proteins become more abundant, they begin to interfere with normal brain and body functions. In turn, this leads to neurological, psychological, and physical issues that continue to worsen and can’t be reversed.
The U.S. National Institutes of Health (NIH) describes Lewy body dementia as both “complex” and “challenging,” in part because many of its hallmark symptoms mirror those of other diseases. Plus, Lewy body dementia carries only vague (rather than definitive) risk factors, making it more difficult to predict. For instance, no particular lifestyle behaviors or genetic tests can be used to conclusively determine one’s likelihood of having Lewy body dementia in the future. That said, neuropsychological tests, blood tests, and scans can help tell if someone who is exhibiting known side effects has Lewy body dementia or a different condition.
The short- and long-term effects of Lewy body dementia

Notable Lewy body dementia side effects include cognitive disruptions (especially memory problems), sleep disorders, hallucinations, and trembling, per the Centers for Disease Control and Prevention. There are several medications that can help people treat and manage dementia symptoms, such as cholinesterase inhibitors and melatonin (via the Lewy Body Dementia Association).
However, the progression of Lewy body dementia can’t be stopped. Consequently, drugs and therapies can only be used for short-term management. Nonetheless, a 2023 review in Disease-a-Month noted the use of various medications for treating certain symptoms, as long as the disease had been accurately diagnosed (as it can sometimes be misdiagnosed as other diseases like Parkinson’s disease).
The NIH estimates that around one million individuals are living with Lewy body dementia, making it the second most common type of dementia (after Alzheimer’s disease). The average time from Lewy body dementia diagnosis to death hovers around five to eight years. According to information available about Ms. Bezos from the Bezos Family Foundation, she lived for five years after receiving a Lewy body dementia diagnosis.