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A randomized, double-blind, placebo-controlled trial of two doses of Ginkgo biloba extract in dementia of the Alzheimer's type
Schneider LS, DeKosky ST, Farlow MR, Tariot PN, Hoerr R, Kieser M.. Current Alzheimer research, 2005-12-01
Topic: Risk, prevention and care in population studies
Context Previous studies of Ginkgo biloba extract (GbE) in patients with various forms of cognitive impairment or dementia have shown promising results. Objective To determine the clinical efficacy of GbE in mild to moderate dementia of the Alzheimer type. Design Randomized, placebo-controlled, double-blind, parallel-group, multicenter trial. Setting Outpatient clinics of universities and private research centers specialized in dementia. Patients 513 outpatients with uncomplicated dementia of the Alzheimer's type scoring 10 to 24 on the Mini-Mental State Examination and less than 4 on the modified Hachinski Ischemic Score, free of other serious illnesses and not requiring continuous treatment with any psychoactive drug. Intervention 26-week treatment with GbE at daily doses of 120 mg or 240 mg or placebo. Main outcomes Cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog), Alzheimer's Disease Cooperative Study Clinical Global Impression of Change (ADCS-CGIC). Results There were no significant between-group differences for the whole sample. There was little cognitive and functional decline of the placebo-treated patients, however. For a subgroup of patients with neuropsychiatric symptoms there was a greater decline of placebo-treated patients and significantly better cognitive performance and global assessment scores for the patients on GbE. Conclusion The trial did not show efficacy of GbE, however, the lack of decline of the placebo patients may have compromised the sensitivity of the trial to detect a treatment effect. Thus, the study remains inconclusive with respect to the efficacy of GbE.
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APA 7th
Schneider, L. S., DeKosky, S. T., Farlow, M. R., Tariot, P. N., Hoerr, R., & Kieser, M. (2005). A randomized, double-blind, placebo-controlled trial of two doses of Ginkgo biloba extract in dementia of the Alzheimer's type. Current Alzheimer research. https://doi.org/10.2174/156720505774932287
Vancouver
Schneider LS, DeKosky ST, Farlow MR, Tariot PN, Hoerr R, Kieser M. A randomized, double-blind, placebo-controlled trial of two doses of Ginkgo biloba extract in dementia of the Alzheimer's type. Current Alzheimer research. 2005. doi:10.2174/156720505774932287. PMID: 16375657.
BibTeX
@article{schneider2005-16375657,
author = {Schneider, L. S. and DeKosky, S. T. and Farlow, M. R. and Tariot, P. N. and Hoerr, R. and Kieser, M.},
title = {{A randomized, double-blind, placebo-controlled trial of two doses of Ginkgo biloba extract in dementia of the Alzheimer's type}},
journal = {Current Alzheimer research},
year = {2005},
doi = {10.2174/156720505774932287},
pmid = {16375657},
url = {https://doi.org/10.2174/156720505774932287}
}
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Key findings
- Context Previous studies of Ginkgo biloba extract (GbE) in patients with various forms of cognitive impairment or dementia have shown promising results.
- Results There were no significant between-group differences for the whole sample.
- For a subgroup of patients with neuropsychiatric symptoms there was a greater decline of placebo-treated patients and significantly better cognitive performance and global assessment scores for the patients on GbE.
Why it matters
In this 26-week trial, Ginkgo biloba extract showed no significant benefit over placebo for the whole group of patients with mild to moderate Alzheimer dementia. A subgroup with neuropsychiatric symptoms showed better scores on Ginkgo, but this was not the main finding.
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Study details
- Evidence strengthHigh
How this study scored 65/100
Published in a peer-reviewed journal, and it is a randomised controlled trial. Scored zero for sample size and effect reported because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Current Alzheimer research) |
| Journal's citation record | 1 / 4 | Current Alzheimer Research: journal h-index 119 (OpenAlex, 2026-10-29) |
| Study design | 11 / 12 | A randomised controlled trial (from PubMed type “Randomized Controlled Trial”) |
| 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 | 2005 — older than 20 years, still counted |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| 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 (pubmed indexes it as a clinical or observational study) |
| Randomised / blinded | 2 / 2 | Randomised and blinded or placebo-controlled (as stated in the record) |
| Times cited | 5 / 7 | Cited 182 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 7.9 citations a year over 23 year(s) since 2005 |
| Impact for its field and year | 5 / 6 | Cited 27.3× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 6 other studies in this library |
| Still being cited | 2 / 4 | Cited 20 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Meinhard Kieser: h-index 61 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | University of Southern California: institution h-index 1,521 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 4 institution(s) in 2 countries |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 16375657) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 65 / 100 | — |
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