The amyloid cascade hypothesis: an updated critical review

Results from recent clinical trials of antibodies that target amyloid-ss (A ss) for Alzheimer's disease have created excitement and have been heralded as corroboration of the amyloid cascade hypothesis. However, while A ss may contribute to disease, genetic, clinical, imaging and biochemical data suggest a more complex aetiology. Here we review the history and weaknesses of the amyloid cascade hypothesis in view of the new evidence obtained from clinical trials of anti-amyloid antibodies. These trials indicate that the treatments have either no or uncertain clinical effect on cognition. Despite the importance of amyloid in the definition of Alzheimer's disease, we argue that the data point to A ss playing a minor aetiological role. We also discuss data suggesting that the concerted activity of many pathogenic factors contribute to Alzheimer's disease and propose that evolving multi-factor disease models will better underpin the search for more effective strategies to treat the disease.

Automated summary

Results from recent clinical trials of anti-amyloid antibodies for Alzheimer's disease have challenged the amyloid cascade hypothesis and indicated a more complex etiology. The treatments have shown no or uncertain clinical effect on cognition, suggesting that amyloid may play a minor role in the disease. Multiple pathogenic factors may contribute to Alzheimer's disease, and evolving multi-factor disease models may lead to more effective treatment strategies.