Author Contributions: Dr Snitz had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Snitz, Carlson, Arnold, Ives, Rapp, Saxton, Lopez, DeKosky.
Acquisition of data: Carlson, Arnold, Ives, Rapp, Saxton, Lopez, Dunn, DeKosky.
Analysis and interpretation of data: Snitz, O’Meara, Carlson, Arnold, Ives, Rapp, Saxton, Lopez, Sink, DeKosky.
Drafting of the manuscript: Snitz, O’Meara, Carlson, Ives, Rapp, Saxton, Lopez, Dunn, Sink, DeKosky.
Critical revision of the manuscript for important intellectual content: O’Meara, Carlson, Arnold, Rapp, Saxton, DeKosky.
Statistical analysis: O’Meara, Arnold.
Obtained funding: Carlson, Lopez, DeKosky.
Administrative, technical, or material support: Snitz, Ives, Rapp, Saxton, Lopez, Dunn, DeKosky.
Study supervision: Snitz, Carlson, Arnold, Ives, Saxton, DeKosky.
Financial Disclosures: Dr Saxton reports having served as a consultant and having received honoraria as a speaker for Pfizer/Eisai and Forest Research Institute. She has received research support from Pfizer/Eisai and receives royalties from Pearson UK for the Severe Impairment Battery. Dr DeKosky reports receiving grants or research support from Elan, Myriad, Neurochem, and GlaxoSmithKline and serving on the advisory boards of or consulting for AstraZeneca, Abbott, Baxter, Daichi, Eisai, Forest, Genentech, GlaxoSmithKline, Lilly, Medivation, Merck, NeuroPharma, Neuroptix, Pfizer, Myriad, and Servier. No other disclosures were reported.
Ginkgo Evaluation of Memory (GEM) Study Investigators: Project Office: Richard L. Nahin, PhD, MPH, Barbara C. Sorkin, PhD, National Center for Complementary and Alternative Medicine. Clinical Centers: Michelle Carlson, PhD, Linda Fried, MD, MPH, Pat Crowley, MS, Claudia Kawas, MD, Paulo Chaves, MD, PhD, Sevil Yasar, MD, PhD, Patricia Smith, Joyce Chabot, John Hopkins University; John Robbins, MD, MHS, Katherine Gundling, MD, Sharene Theroux, CCRP, Lisa Pastore, CCRP, University of California, Davis; Lewis Kuller, MD, DrPH, Roberta Moyer, CMA, Cheryl Albig, CMA, University of Pittsburgh; Gregory Burke, MD, Steve Rapp, PhD, Dee Posey, Margie Lamb, RN, Wake Forest University School of Medicine. Schwabe Pharmaceuticals: Robert Hörr, MD, Joachim Herrmann, PhD. Data Coordinating Center: Richard A. Kronmal, PhD, Annette L. Fitzpatrick, PhD, Fumei Lin, PhD, Cam Solomon, PhD, Alice Arnold, PhD, University of Washington. Cognitive Diagnostic Center: Steven DeKosky, MD, Judith Saxton, PhD, Oscar Lopez, MD, Beth Snitz, PhD, M. Ilyas Kamboh, PhD, Diane Ives, MPH, Leslie Dunn, MPH, University of Pittsburgh. Clinical Coordinating Center: Curt Furberg, MD, PhD, Jeff Williamson, MD, MHS, Nancy Woolard, Kathryn Bender, PharmD, Susan Margitić, MS, Wake Forest University School of Medicine. Central Laboratory: Russell Tracy, PhD, Elaine Cornell, UVM, University of Vermont. Magnetic Resonance Imaging Reading Center: William Rothfus MD, Charles Lee MD, Rose Jarosz, University of Pittsburgh. Data and Safety Monitoring Board: Richard Grimm, MD, PhD (chair), University of Minnesota; Jonathan Berman, MD, PhD (executive secretary), National Center for Complementary and Alternative Medicine; Hannah Bradford, MAc, LAc, MBA, Carlo Calabrese, ND, MPH, Bastyr University Research Institute; Rick Chappell, PhD, University of Wisconsin Medical School; Kathryn Connor, MD, Duke University Medical Center; Gail Geller, ScD, Johns Hopkins Medical Institute; Boris Iglewicz, PhD, Temple University; Richard S. Panush, MD, St Barnabas Medical Center; Richard Shader, PhD, Tufts University.
Funding/Support: This work was funded by grant U01 AT000162 from the NCCAM and the Office of Dietary Supplements and by support from the National Institute on Aging, National Heart, Lung, and Blood Institute, University of Pittsburgh Alzheimer's Disease Research Center (grant P50AG05133), Roena Kulynych Center for Memory and Cognition Research, and National Institute of Neurological Disorders and Stroke. We gratefully acknowledge Schwabe Pharmaceuticals, Karlsruhe, Germany, for donation of G biloba tablets and identical placebos.
Role of the Sponsor: The NCCAM of the National Institutes of Health contributed to the design and conduct of the study as well as analysis and interpretation of the data and review and approval of the manuscript. Schwabe Pharmaceuticals had no role in the design and conduct of the study; analysis and interpretation of the data; or preparation or approval of the manuscript. Schwabe was provided a copy of the manuscript to review and comment on prior to submission for publication, predominantly to correct any factual errors regarding the product used in the study. There was no requirement that any comments or suggestions had to be included in the final submitted manuscript, and the review did not influence the scientific content of the manuscript.
Disclaimer: This report's contents are solely the responsibility of the authors and do not necessarily represent the official views of the NCCAM or the National Institutes of Health.
Additional Contributions: We are indebted to Stephen Straus, MD, late former director of the NCCAM, who championed efforts to evaluate complementary and alternative therapies in rigorous scientific fashion. We are also grateful to our volunteers, whose faithful participation in this longitudinal study made it possible.