Despite global efforts to understand and ultimately assess, diagnose, and treat Alzheimer's disease (AD) more effectively, a consensus definition of AD still does not exist.  In 2018, the National Institute of Aging – Alzheimer’s Association (NIA-AA) Research Framework recommended that we should shift the definition of AD from a syndrome (i.e., the cognitive/behavioral symptoms that individuals present with) to a purely biological construct, specifically the presence of βamyloid deposition, pathologic tau, and neurodegeneration (the "A/T/N" model).  In this episode, we talk to Dr. Adam Brickman about the NIA-AA Research Framework biological definition of AD, the role of vascular contributions, assumptions about the amyloid hypothesis, and implications of not including the clinical syndrome in the diagnosis of AD. Show notes are available at www.NavNeuro.com/19 _________________ If you’d like to support the show, here are a few easy ways: 1) Tell your friends and colleagues about it 2) Subscribe (free) and leave an iTunes review: www.NavNeuro.com/itunes 3) Contribute to the discussion in the comments section of the website (click the episode link listed above) or on Twitter (@NavNeuro)   Thanks for listening, and join us next time as we continue to navigate the brain and behavior!   [Note: This podcast and all linked content is intended for general educational purposes only and does not constitute the practice of psychology or any other professional healthcare advice and services. No professional relationship is formed between hosts and listeners. All content is to be used at listeners’ own risk.  Users should always seek appropriate medical and psychological care from their licensed healthcare provider.]