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Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up
Valenzuela M, Sachdev P.. The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry, 2009-03-01
Topic: Risk, prevention and care in population studies
Objectives Epidemiological and preclinical studies suggest that mental activity levels may alter dementia risk. Clinical trials are now beginning to address the key issues of persistence of effect over extended follow-up and transfer of effect to nontrained domains. The aim of this report was to therefore systematically review results from clinical trials, which have examined the effect of cognitive exercise on longitudinal cognitive performance in healthy elderly individuals. Methods MEDLINE, PubMed, and key references were used to generate an initial list of relevant studies (N = 54). These were reviewed to identify randomized controlled trials, which tested the effect of a discrete cognitive exercise training regime on longitudinal (>3 months) posttraining neuropsychological performance in healthy older adults. Seven RCTs met entry criteria. Prechange and postchange scores were integrated using a random effects weighted mean difference (WMD) meta-analytic approach (Review Manager Version 4.2). Results A strong effect size was observed for cognitive exercise interventions compared with wait-and-see control conditions (WMD = 1.07, CI: 0.32-1.83, z = 2.78, N = 7, p = 0.006, N = 3,194). RCTs with follow-up greater than 2 years did not appear to produce lower effect size estimates than those with less extended follow-up. Quality of reporting of trials was in general low. Conclusion Cognitive exercise training in healthy older individuals produces strong and persistent protective effects on longitudinal neuropsychological performance. Transfer of these effects to dementia-relevant domains such as general cognition and daily functioning has also been reported in some studies. Importantly, cognitive exercise has yet to be shown to prevent incident dementia in an appropriately designed trial and this is now an international priority.
Key findings
- Objectives Epidemiological and preclinical studies suggest that mental activity levels may alter dementia risk.
- The aim of this report was to therefore systematically review results from clinical trials, which have examined the effect of cognitive exercise on longitudinal cognitive performance in healthy elderly individuals.
- Results A strong effect size was observed for cognitive exercise interventions compared with wait-and-see control conditions (WMD = 1.07, CI: 0.32-1.83, z = 2.78, N = 7, p = 0.006, N = 3,194).
Why it matters
This systematic review of seven randomized controlled trials found that cognitive exercise interventions improved cognitive performance in healthy older adults compared with wait-and-see controls. However, the review notes that quality of reporting was generally low, and it does not show that cognitive exercise prevents dementia onset.
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Study details
- Study designlongitudinal study
- Participants54
- Evidence strengthHigh
How this study scored 66/100
Published in a peer-reviewed journal, and it is a systematic review of all the studies on the question. Scored zero for effect reported because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry) |
| Journal's citation record | 2 / 4 | American Journal of Geriatric Psychiatry: journal h-index 178 (OpenAlex, 2026-10-29) |
| Study design | 12 / 12 | A systematic review of all the studies on the question (from PubMed type “Systematic Review”) |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2009 — within 20 year(s) of the newest study here |
| Sample size | 1 / 4 | 54 participants |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 3 / 3 | Studied in people (participant count stated) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | 6 / 7 | Cited 345 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 18.2 citations a year over 19 year(s) since 2009 |
| Impact for its field and year | 3 / 6 | Cited 3.9× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 12 other studies in this library |
| Still being cited | 2 / 4 | Cited 26 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Perminder Singh Sachdev: h-index 147 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | UNSW Sydney: institution h-index 1,101 (OpenAlex) |
| Multi-centre collaboration | 1 / 3 | OpenAlex lists 2 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 19225276) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 66 / 100 | — |
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Cite this study APA, Vancouver, BibTeX · download .bib or .ris
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APA 7th
Valenzuela, M., & Sachdev, P. (2009). Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up. The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry. https://doi.org/10.1097/jgp.0b013e3181953b57
Vancouver
Valenzuela M, Sachdev P. Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up. The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry. 2009. doi:10.1097/jgp.0b013e3181953b57. PMID: 19225276.
BibTeX
@article{valenzuela2009-19225276,
author = {Valenzuela, M. and Sachdev, P.},
title = {{Can cognitive exercise prevent the onset of dementia? Systematic review of randomized clinical trials with longitudinal follow-up}},
journal = {The American journal of geriatric psychiatry : official journal of the American Association for Geriatric Psychiatry},
year = {2009},
doi = {10.1097/jgp.0b013e3181953b57},
pmid = {19225276},
url = {https://doi.org/10.1097/jgp.0b013e3181953b57}
}
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