Alzheimer's Definitions, Biomarkers, and Antibodies: Halima Amjad, Barak Gaster, and Heather Whitson

Mar 12, 2026

It’s an era of breakthroughs in Alzheimer’s research, yet for many clinicians, it’s also a time of profound uncertainty. We are currently navigating competing definitions of the disease, multiple new biomarkers coming on market seemingly every week, and the clinical rollout of new amyloid antibodies.

How do we translate this rapid-fire science into daily practice? On this week’s GeriPal podcast, we sit down with dementia experts Halima Amjad, Barak Gaster, and Heather Whitson. We dive deep into:

• The evolving definitions of Alzheimer’s disease.  Does someone have Alzheimer's disease if you have only an abnormal biomarker as defined by the Alzheimer's Association, or is amyloid pathology necessary but not sufficient to define Alzheimer's as per the International Working Group (IWG) recommendations?

• Where do blood-based biomarkers for Alzheimer's fit into the diagnostic workup, and should they be used at all in primary care?  FYI - here is my take on that question in a recent JAMA IM article titled “The Limited Role of Alzheimer's Disease Blood-Based Biomarkers in Primary Care.”

• What’s the role of amyloid antibodies in the care of individuals with Alzheimer's disease, including who to use them on?

We covered a lot and discussed some of these resources that you can do a deeper dive on:

• Blood-based biomarker resources

• JAMA article on Blood-Based Biomarkers for Alzheimer's Disease: Preventing Unintended Consequences 

• Alzheimer's Dementia article on Blood-based biomarkers for detecting Alzheimer's disease pathology in cognitively impaired individuals within specialized care settings: A systematic review and meta-analysis

• JAMA IM article on The Limited Role of Alzheimer Disease Blood-Based Biomarkers in Primary Care

• Appropriate use recommendations for amyloid antibodies

• Donanemab: Appropriate use recommendations 

• Lecanemab: Appropriate Use Recommendations

• Primary Care Resources

• Cognition in Primary Care program

• A JAGS article on “Large Health System Quality Improvement Intervention Providing Training and Tools to Improve Detection of Cognitive Impairment in Primary Care”

• Other resources

• AGS’s new online curriculum for Alzheimer’s Disease

By Eric Widera