Cognitive Speed Training with Booster Sessions Linked to Reduced Dementia Risk Over 20 Years

20-Year ACTIVE Study: Cognitive Speed Training with Boosters Linked to 25% Lower Dementia Risk

A 20-year follow-up study of the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) trial indicates that older adults who completed cognitive speed training, reinforced with booster sessions, had a statistically significant 25% lower risk of being diagnosed with dementia, including Alzheimer's disease and related dementias (ADRD), compared to a control group. The findings, published in Alzheimer's & Dementia: Translational Research and Clinical Interventions, suggest that this specific nonpharmacological intervention may have long-term protective effects against dementia onset.

This long-term follow-up reveals that a specific nonpharmacological intervention—cognitive speed training with booster sessions—may offer significant protection against dementia onset, reducing risk by 25%.

Study Design and Methodology

The ACTIVE study, funded by the National Institutes of Health (NIH), initially enrolled 2,802 community-dwelling adults aged 65 and older in 1998–99. Participants were randomly assigned to one of three cognitive training groups—memory, reasoning, or speed of processing—or a no-contact control group.

Eligibility criteria included a Mini-Mental State Examination score of 23 or higher and independence in daily living activities. Exclusions included conditions such as recent stroke or ongoing cancer treatment.

Participants in the training groups completed up to 10 sessions, each lasting 60–75 minutes, over a period of five to six weeks. Approximately half of these participants were also randomized to receive up to four additional "booster" training sessions administered at 11 and 35 months after the initial training.

For the 20-year follow-up, researchers reviewed Medicare claims data from 2,021 participants (72% of the original cohort) between 1999 and 2019 to identify dementia diagnoses using the Chronic Conditions Warehouse algorithm. At the study's commencement, the cohort's average age was 74, with approximately three-fourths being women and 70% white.

Key Findings

The long-term analysis revealed a significant protective effect for a specific intervention. Participants in the speed-of-processing training group who received booster sessions demonstrated a statistically significant 25% lower risk of an ADRD diagnosis compared to the control group.

Specifically, 105 out of 264 (40%) participants in the boosted speed-training group received a dementia diagnosis, compared to 239 out of 491 (49%) in the control group. The adjusted hazard ratio was 0.75 (95% CI 0.59 to 0.95).

In contrast, speed-trained participants who did not receive booster sessions showed no statistically significant protective benefit against dementia. Similarly, training focused on memory or reasoning skills, even with booster participation, did not demonstrate a statistically significant reduction in long-term dementia risk.

Previous analyses of the ACTIVE trial had indicated that all three training arms improved everyday function at 10 years, and speed training was associated with a 29% lower incidence of dementia at 10 years.

Proposed Mechanisms of Action

Researchers hypothesize that the effectiveness of the speed-of-processing training may stem from several factors:

• Adaptive Nature: The training program adjusted its challenge level based on each participant's performance, allowing for individualized progression.
• Implicit Learning: Speed training is thought to promote implicit learning, which involves the acquisition of unconscious or automatic skills. This type of learning differs from explicit learning, which involves conscious facts and strategies, and is believed to engage distinct brain processes that may be more resistant to age-related decline and lead to more durable changes and increased brain connectivity.
• Targeted Skills: The training specifically focused on enhancing visual attention, rapid information processing, and divided attention, skills considered critical for daily tasks. The training involves tasks such as quickly identifying a central image and a peripheral item on a computer screen, with increasing difficulty as performance improves. The "Double Decision" game, commercially available via BrainHQ, exemplifies this type of training.

Expert Commentary and Implications

Marilyn Albert, Ph.D., corresponding study author and director of the Alzheimer's Disease Research Center at Johns Hopkins Medicine, noted the significance of the findings.

"The link between boosted speed training and lower dementia risk two decades later suggests that a modest nonpharmacological intervention can have long-term effects," Dr. Albert stated, adding that even slight delays in dementia onset could impact public health and healthcare costs.

George Rebok, Ph.D., a site principal investigator, suggested that the findings support the development of cognitive training interventions, particularly those targeting visual processing and divided attention abilities.

Michael Marsiske, another principal investigator, observed that the training benefits did not substantially decrease with age, indicating that individuals may begin cognitive training at any time. Dr. Henry Mahncke, CEO of Posit Science (which owns BrainHQ), stated that this speed training was developed to promote neuroplasticity, helping the brain process visual information more quickly and accurately.

Understanding Dementia

Dementia is characterized by a decline in thinking abilities that affects an individual's capacity to live independently. It is estimated to affect 42% of adults over age 55 at some point in their lives and incurs over $600 billion annually in U.S. costs. Alzheimer's disease accounts for 60%–80% of dementia cases.

Future Research and Limitations

The authors suggest that combining cognitive training with other lifestyle interventions, such as maintaining cardiovascular health, engaging in regular physical activity, nutrition, and hypertension management, may further delay dementia onset.

An ongoing study, the Preventing Alzheimer's with Cognitive Training (PACT) study, funded by the National Institutes of Health, is currently enrolling approximately 7,500 individuals aged 65 and older. This study aims to investigate the effects of a more intensive training regimen, with participants completing 45 sessions over several years, and initial results are anticipated around 2028.

Limitations of the current study include its reliance on Medicare claims-based diagnoses for ADRD, which may impact the classification of true dementia cases, and the exclusion of Medicare Advantage enrollees, potentially limiting generalizability. A high death rate of 77% occurred across all groups over the 20-year follow-up, consistent with the cohort's advanced age. Further confirmation with clinically adjudicated outcomes is warranted.