The Alzheimer's Disease Neuroimaging Initiative (ADNI) has accumulated 18 years of clinical, neuroimaging, cognitive, biomarker and genetic data, and biofluid samples available to researchers, resulting in more than 4,000 publications.
Since its inception, the overall goal of ADNI has been to investigate the use of biomarkers in AD clinical trials, to predict and monitor cognitive decline across the AD continuum.
In a new review of past publications, subgroups of all diagnostic classes were identified based on cognition, MRI, and blood proteins and metabolites and differed in associations with cognitive domains, AD biomarkers, and underlying genetics and biochemistry, supporting their biological coherence. Additional factors modulating disease trajectory included cerebrovascular disease acting to exacerbate AD by multiple mechanisms, inflammation, cognitive and brain reserve, and sex differences.
Improvements to clinical trials hinge on a more nuanced understanding of disease progression and included fine-tuning of selection tools, determining the time frame of progression, and modifications to outcome measures.
A major limitation of ADNI is its strict inclusion and exclusion criteria that have resulted in a highly educated largely European cohort with few comorbidities. ADNI participants are not representative of the wider general population and therefore the studies using ADNI data described in their review may not necessarily ensure generalizability.
One goal of a renewal application to the NIA will be to increase generalizability by reducing the exclusion criteria (e.g., allowing more cerebrovascular disease), increasing the ethnocultural diversity of newly enrolled participants, and recruiting individuals with lower levels of education.
You can review the entirety of their findings at NIH.gov.