Brain training could reduce dementia risk by 25% in 20-year study

A 20-year randomised trial of more than 2,000 people aged 65+ found that an adaptive, speeded divided-attention task paired with booster sessions was associated with about a 25% lower dementia diagnosis rate; authors and outside experts say important limitations mean the result is not conclusive.

A long-term trial reports an association between a specific brief brain training programme and lower rates of dementia diagnosis. Researchers followed more than 2,000 people aged 65 and older for 20 years after randomly assigning them to three types of cognitive training or a control group. One intervention used an adaptive, speeded divided-attention computer task called Double Decision, and some participants received booster sessions at later dates. Study authors reported that participants who did the speed training with booster sessions had about a 25% lower dementia diagnosis rate compared with the control group. Key findings: - Study design: a randomised trial of over 2,000 participants aged 65+, with initial training twice weekly for five weeks and some participants later receiving booster sessions. - Intervention detail: the speeded task (Double Decision) is adaptive and focuses on divided attention and visual speed of processing. - Main outcome: after 20 years the speed-training group with boosters showed an approximately 25% lower dementia diagnosis rate versus controls; other groups, including speed training without boosters, did not show significant changes. - Limitations: dementia diagnoses were identified through health records rather than standardized clinical assessments, and the participant group tended to be healthier than average, which may bias results. - Expert reactions: the study was described as a valuable long-term contribution, but statisticians and Alzheimer’s Research UK cautioned that the evidence is not sufficient to demonstrate prevention and that primary analyses did not show clear significant differences. Summary: The trial reports an association between adaptive, speeded divided-attention training with booster sessions and a lower dementia diagnosis rate over 20 years, while other training arms showed no significant effect. Undetermined at this time.