Brain scans begin for nationwide Alzheimer’s disease study

One of the first to participate in the study, called Clarity in Alzheimer’s Disease and Related Dementias Research Through Imaging, or CLARiTI, is Barbara Smith Ballen of Dane County. The 70-year-old mother of five began volunteering for research studies at the Wisconsin Alzheimer’s Disease Research Center in 2018 and enrolled in CLARiTI in 2024. Smith Ballen’s father was diagnosed with dementia in the years leading up to this death, which motivated her to become a research participant.

“I am committed to doing whatever I can to help end this devastating disease and hopefully others will follow my lead,” she said. “I truly believe that this research team has what it takes to make a breakthrough; they just need to stay persistent.”

The five-year study, which launched participant brain scanning in August 2024, involves 37 National Institutes of Health-funded Alzheimer’s Disease Research Centers across the United States. Researchers will gather data correlated with presence, absence or changes in characteristic disease biomarkers in people who have dementia or are at risk of developing it. The study is also intended to allow a better understanding of mixed dementia, which is a situation in which more than one neurological disease contributes to dementia, according to Sterling Johnson, study leader and professor of medicine at the UW School of Medicine and Public Health.

“Multiple etiologies can contribute to the clinical syndrome of mild cognitive impairment and dementia presumed to be due to Alzheimer’s disease, but it can be difficult to pinpoint exactly what those contributors are for each person,” said Johnson, who holds a doctorate in clinical neuropsychology. “If we can establish a more comprehensive panel of imaging and blood plasma biomarkers, we stand to greatly improve the accuracy and prediction of symptom course as well as a patient’s response to experimental therapies.”

The team in Madison is co-leading the administration and launch of CLARiTI and was selected to pilot the first series of brain scans through the Wisconsin Alzheimer’s Disease Research Center because of the center’s established network of participants, according to Sarah Biber, CLARiTI co-lead for administration and site and data coordination, and executive director of the National Alzheimer’s Coordinating Center based at the University of Washington.

“We are confident this collaboration will allow our team to work through any issues together to improve the process and lay the groundwork for sites that will join the study,” said Biber, who holds a doctorate in molecular and cellular biology. “The data we collect in Madison and subsequent sites is expected to significantly enhance our understanding of mixed etiology dementia.”

The comprehensive panel developed by the CLARiTI team includes state-of-the-art imaging and blood-based biomarkers which will be shared with Alzheimer’s disease and related dementia researchers worldwide. This will allow researchers to correlate biological changes to clinical diagnoses, genetics and changes in patient symptoms over time. The team aims to enroll a total of 2,000 people for brain imaging and blood-based biomarkers. All participants will undergo baseline scans first and then return within two years for another set of scans to compare changes within the brain. All CLARiTI study sites are expected to be operational by 2025, according to Johnson.

“A collaboration of this size addresses a crucial research gap and paves the way for standardized blood-biomarker characterization,” he said. “By working together, these centers can collect, share and analyze hundreds of unique imaging and plasma sets, which will be intrinsically linked to cognitive and neurobehavioral data collection, genetics and eventually neuropathology.”

Within CLARiTI, a dedicated inclusion team is focused on ensuring that at least 25 percent of participants recruited into CLARiTI come from communities historically underrepresented in research. Black and Latinx adults are twice as likely to have dementia from all causes including Alzheimer’s disease, but are one-third less likely to receive a diagnosis, making it imperative to include these groups in any Alzheimer’s research, according to Ozioma Okonkwo, CLARiTI inclusion core co-lead and professor of medicine at the UW School of Medicine and Public Health.

“These groups often experience a greater severity of initial cognitive symptoms at a younger age than their white counterparts,” he said. “A critical component of our efforts is to gain the trust of these communities so that, by enrolling them in CLARiTI, we can gain better understanding of the factors that contribute to these health inequities, and also ensure that our findings are applicable to everyone affected by these devastating conditions.”

The inclusion team has identified a set of culturally informed, community-engaged research methods as part of this recruitment effort including focusing on ways that the CLARiTI team can serve communities beyond the study recruitment effort. This approach will also embrace more intensive personal contact and participation in community events, according to Okonkwo.

“We know social determinants of health have a huge impact on a variety of diseases, including Alzheimer’s and related dementias,” he said. “This is why it is absolutely essential to take a comprehensive approach to our work; not only do we examine the biological alterations that trigger the cascade of brain changes in Alzheimer’s but we also take proper stock of the range of life experiences that impact these changes in the brain.”

Data generated from CLARiTI will be made available to the scientific community through the National Alzheimer’s Coordinating Center, and biological samples will be analyzed and made available through the National Centralized Repository for Alzheimer’s Disease and Related Dementias. Centralizing access to data and samples is intended to significantly accelerate scientific discovery within the Alzheimer’s Disease Research Centers network and beyond.