Home › Research › Treatments
A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. North American EGb Study Group
Le Bars PL, Katz MM, Berman N, Itil TM, Freedman AM, Schatzberg AF.. JAMA, 1997-10-01
Topic: Risk, prevention and care in population studies
Context EGb 761 is a particular extract of Ginkgo biloba used in Europe to alleviate symptoms associated with numerous cognitive disorders. Its use in dementias is based on positive results from only a few controlled clinical trials, most of which did not include standard assessments of cognition and behavior. Objective To assess the efficacy and safety of EGb in Alzheimer disease and multi-infarct dementia. Design A 52-week, randomized double-blind, placebo-controlled, parallel-group, multicenter study. Patients Mildly to severely demented outpatients with Alzheimer disease or multi-infarct dementia, without other significant medical conditions. Intervention Patients assigned randomly to treatment with EGb (120 mg/d) or placebo. Safety, compliance, and drug dispensation were monitored every 3 months with complete outcome evaluation at 12, 26, and 52 weeks. Primary outcome measures Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog), Geriatric Evaluation by Relative's Rating Instrument (GERRI), and Clinical Global Impression of Change (CGIC). Results From 309 patients included in an intent-to-treat analysis, 202 provided evaluable data for the 52-week end point analysis. In the intent-to-treat analysis, the EGbgroup had an ADAS-Cog score 1.4 points better than the placebo group (P=.04) and a GERRI score 0.14 points better than the placebo group (P=.004). The same patterns were observed with the evaluable data set in which 27% of patients treated with EGb achieved at least a 4-point improvement on the ADAS-Cog, compared with 14% taking placebo (P=.005); on the GERRI, 37% were considered improved with EGb, compared with 23% taking placebo (P=.003). No difference was seen in the CGIC. Regarding the safety profile of EGb, no significant differences compared with placebo were observed in the number of patients reporting adverse events or in the incidence and severity of these events. Conclusions EGb was safe and appears capable of stabilizing and, in a substantial number of cases, improving the cognitive performance and the social functioning of demented patients for 6 months to 1 year. Although modest, the changes induced by EGb were objectively measured by the ADAS-Cog and were of sufficient magnitude to be recognized by the caregivers in the GERRI.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Le Bars, P. L., Katz, M. M., Berman, N., Itil, T. M., Freedman, A. M., & Schatzberg, A. F. (1997). A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. North American EGb Study Group. JAMA. https://doi.org/10.1001/jama.278.16.1327
Vancouver
Le Bars PL, Katz MM, Berman N, Itil TM, Freedman AM, Schatzberg AF. A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. North American EGb Study Group. JAMA. 1997. doi:10.1001/jama.278.16.1327. PMID: 9343463.
BibTeX
@article{lebars1997-9343463,
author = {Le Bars, P. L. and Katz, M. M. and Berman, N. and Itil, T. M. and Freedman, A. M. and Schatzberg, A. F.},
title = {{A placebo-controlled, double-blind, randomized trial of an extract of Ginkgo biloba for dementia. North American EGb Study Group}},
journal = {JAMA},
year = {1997},
doi = {10.1001/jama.278.16.1327},
pmid = {9343463},
url = {https://doi.org/10.1001/jama.278.16.1327}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
Key findings
- Context EGb 761 is a particular extract of Ginkgo biloba used in Europe to alleviate symptoms associated with numerous cognitive disorders.
- Its use in dementias is based on positive results from only a few controlled clinical trials, most of which did not include standard assessments of cognition and behavior.
- Patients Mildly to severely demented outpatients with Alzheimer disease or multi-infarct dementia, without other significant medical conditions.
- Results From 309 patients included in an intent-to-treat analysis, 202 provided evaluable data for the 52-week end point analysis.
- The same patterns were observed with the evaluable data set in which 27% of patients treated with EGb achieved at least a 4-point improvement on the ADAS-Cog, compared with 14% taking placebo (P=.005); on the GERRI, 37% were considered improved with EGb, compared with 23% taking placebo (P=.003).
Why it matters
In this 52-week trial, patients taking Ginkgo biloba extract had slightly better scores than placebo on some measures of cognition and behavior. The study was designed to assess symptoms in people who already had dementia, not to prevent or cure the disease.
New to this subject? Start with our plain-English guide: Treatments →
Study details
- Participants309
- Evidence strengthHigh
How this study scored 76/100
Published in a top-tier journal, and it is a randomized controlled trial. Scored zero for effect reported because the record does not state it. We have no data on senior author's track record and institution's track record, so those were left out: it earned 71 of the 93 points we could judge it on, which is 76 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 10 / 10 | Tier 1 — top-tier general journal (JAMA) |
| Journal's citation record | 4 / 4 | JAMA: journal h-index 1,011 (OpenAlex, 2026-10-29) |
| Study design | 11 / 12 | A randomized 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 | 1997 — older than 20 years, still counted |
| Sample size | 2 / 4 | 309 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) |
| Randomized / blinded | 2 / 2 | Randomized and blinded or placebo-controlled (as stated in the record) |
| Times cited | 6 / 7 | Cited 605 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 19.5 citations a year over 31 year(s) since 1997 |
| Impact for its field and year | 6 / 6 | Cited 76.6× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 3 / 6 | Cited by 18 other studies in this library |
| Still being cited | 1 / 4 | Cited 10 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | — / 4 | OpenAlex's profile for last-listed author P L Le Bars holds only 4 work(s), too few to judge a track record — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multicenter collaboration | 2 / 3 | PubMed indexes it as a multicentre study |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 9343463) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 71 / 93 | Scored on 18 of 20 parts. We have no data for the rest, so they are left out: 71 of the 93 points we could judge it on is 76 out of 100. |
| Total | 76 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
May need a subscription Unpaywall, Europe PMC and OpenAlex found no free copy of the full text (checked 10 Oct 2026), so the publisher may charge for it. The PubMed abstract is free.
Related
Studies in the library that share something with this one. The line above each title says what.
Later studies that cite this one
18 studies in the alzhub library list this one in their references. Showing the 8 highest-scoring.
Related studies in Treatments
Also tagged “placebo-controlled”
783 studies in the library carry the topic tag “placebo-controlled”; these are this study's neighbours in a fixed, alphabetical-by-hash tour of them, not the closest in content. All 783 tagged studies.