A recent editorial published in JAMA Neurology by Brian Appleby, MD (Clinical Core and Neuropathology Core) and Mark Cohen, MD (Neuropathology Core) examines an emerging and highly debated question in neurodegeneration: can Alzheimer disease ever be transmitted through medical procedures? Drawing on newly reported cases involving individuals who received cadaver-derived human growth hormone decades ago, the authors carefully evaluate claims that these patients later developed what has been termed “iatrogenic Alzheimer disease.”

The discussion centers on a small number of patients from a United Kingdom cohort, who were exposed to historical growth hormone preparations that are no longer in use. Some of these individuals developed cognitive symptoms at relatively young ages, and in rare cases, Alzheimer-type pathology has been identified. While these findings raise important scientific questions, the authors emphasize that the current evidence supports transmission of amyloid-β pathology only, not Alzheimer disease itself.

Published online on March 30, 2026, the editorial places these findings in the broader context of decades of prion disease research and highlights the biological plausibility of protein misfolding spreading under very specific conditions. However, the authors stress that the available data remain limited, heterogeneous, and insufficient to establish causation.

The purpose of this work is to provide clarity and caution. The authors underscore the importance of rigorous diagnostic standards, careful interpretation of emerging data, and responsible communication with the public. Importantly, they note that these historical cases do not suggest that Alzheimer disease is contagious or transmissible in modern medical care.

For patients, families, and clinicians, the key message is reassurance: current medical practices do not pose a risk of transmitting Alzheimer disease. At the same time, ongoing research into protein misfolding and neurodegeneration remains essential, both for understanding disease mechanisms and for advancing future treatments.