Brandeis Stories

By David Levin
March 17, 2026 • Research

For years, studies have shown that brain cells producing dopamine—a chemical that plays a central role in memory—start to die off as people age. This doesn’t necessarily mean that memory declines as well: the Dopamine-making cells that are left can often ramp up their production to compensate, leaving brain function normal.

Findings like this have suggested that boosting dopamine could protect aging brains, including those with Alzheimer's disease. A new study by Brandeis neuroscientist Anne Berry, however, is putting a big caveat in that claim. In healthy older adults, her lab found, higher dopamine levels are indeed connected to better memory, but in adults with early signs of Alzheimer’s disease, the findings are reversed: more dopamine seems to make memory worse. The paper was published in February in the Journal of Neuroscience.

During the study, Berry and her colleagues used PET scans to track a group of older adults over time, tracking how much dopamine their brains created, and whether they contained the tau protein tangles and amyloid-beta protein “plaques”, that are a hallmark of Alzheimer's. Her team also asked the study’s participants to do a series of memory-intensive tasks in an fMRI machine to determine how well their memory recall worked.

"We think the extra dopamine is actually too much to handle for the system that consolidates memories," Berry says. "It's kind of like overdosing the system."  
The stakes are practical. Drugs like Ritalin, which enhance dopamine levels in the brain, initially seemed promising as a cognitive aid for aging adults — yet Berry's work suggests that whether such drugs help or harm depends entirely on a patient's underlying brain health.
"It really informs precision medicine," she says. "You really need to be accounting for these other factors."