Researchers report that a long-running randomized controlled trial found older adults who completed a specific speed-focused brain-training exercise had about a 25% lower risk of being diagnosed with dementia over roughly 20 years compared with a control group. The finding, described by study authors as surprising and important, comes from follow-ups that used health-record diagnoses to track outcomes.
The trial enrolled older adults and randomly assigned participants to one of three training programs (speed, memory, or reasoning) or to a no-training control. Training consisted of roughly one to two 60–75 minute sessions per week for about five to six weeks, with some participants later invited to return for booster sessions one and three years after initial training. The speed exercise tested in the study is a computer task often called "Double Decision," an adaptive, dual-attention task that grows harder as performance improves.
