NEW long-term evidence demonstrates that cognitive training focused on processing speed can significantly reduce the risk of a dementia diagnosis decades later, offering one of the strongest indications yet that targeted brain training could alter long-term cognitive health trajectories.
A Landmark Trial Revisits Cognitive Training Outcomes
The findings come from extended follow-up of the Advanced Cognitive Training for Independent and Vital Elderly study, a large randomised controlled trial originally designed to test whether cognitive training could help older adults maintain everyday mental function. Researchers have now linked trial data to US Medicare claims over 20 years, allowing assessment of real-world dementia diagnoses rather than short-term cognitive test scores.
Methods and Results From a 20 Year Follow Up
The analysis included 2,021 participants enrolled in traditional Medicare at baseline and tracked claims data from 1999 to 2019. Participants were originally randomised to memory training, reasoning training, speed-of-processing cognitive training, or a control group. Dementia outcomes were identified using the Chronic Conditions Warehouse algorithm. Only participants in the speed-training arm who completed one or more booster sessions showed a significantly reduced risk of diagnosed Alzheimer’s disease and related dementias, with a hazard ratio of 0.75 (95% CI: 0.59, 0.95). Those who received speed training without boosters showed no benefit (HR: 1.01, 95% CI: 0.81, 1.27). Memory and reasoning training produced no statistically significant reduction in dementia risk.
Implications for Clinical Practice and Prevention
These results suggest that cognitive training is not universally effective, but that specific formats matter. Speed-based, adaptive, dual-attention tasks reinforced with booster sessions appear capable of producing long-lasting protective effects.
For clinicians, this raises the possibility of prescribing structured cognitive interventions as part of midlife or early older-age prevention strategies, particularly for individuals at elevated dementia risk. Importantly, the findings also indicate that one-off interventions may be insufficient, and that repeated, adaptive training may be necessary to support durable neuroplastic changes.
While further studies are needed to clarify mechanisms and confirm generalisability, this work provides the strongest evidence to date that targeted cognitive interventions could delay dementia diagnosis, shifting prevention efforts beyond lifestyle advice alone.
Reference
COE NB et al. Impact of cognitive training on claims-based diagnosed dementia over 20 years: evidence from the ACTIVE study. Alzheimers Dement (Transl Res Clin Interv). 2026;DOI:10.1002/trc2.70197.
