Harvard Health Experts and Contributors

List of Experts

photo of Samar Hafida, MD

Samar Hafida, MD


Samar Hafida, MD, is an adult endocrinologist at Joslin Diabetes Center in Boston, MA. Her special interests include weight management and the effect of metabolic surgery in the management of type 2 diabetes. In addition to her clinical work, Dr. Hafida is passionate about medical education and delivery of diabetes care to health systems. She is assistant director of global education and is involved in several education initiatives geared to a wide variety of learners and provides consultation to health systems on reforming diabetes care and improving outcomes.
Read more about Samar Hafida, MD
photo of Kathleen Haley, MD

Kathleen Haley, MD


Kathleen J. Haley, MD, is a physician in the Pulmonary and Critical Care Division at the Brigham and Women’s Hospital. She graduated from the Pennsylvania State University College of Medicine and then completed an Internal Medicine Residency at the New England Deaconess Hospital followed by fellowships in Pulmonary Medicine at the New England Deaconess Hospital and Critical Care Medicine at the Brigham and Women’s Hospital. Dr. Haley is an Assistant Professor of Medicine at Harvard Medical School and an Associate Physician at the Brigham and Women’s Hospital, where she attends in the Medical and Thoracic Intensive Care Units. Additionally, she serves as the Medical Director for the BWH Ventilator Service at Spaulding Hospital Cambridge. She is active in clinical research, where her interests include asthma and chronic critical illness.
Read more about Kathleen Haley, MD
photo of Daniel L. Hall, PhD

Daniel L. Hall, PhD


Daniel L. Hall, PhD, is a licensed clinical health psychologist, Harvard Medical School integrative medicine research fellow, and a clinical fellow in psychology in the department of psychiatry at Massachusetts General Hospital (MGH). He works with clinical research teams at the MGH Behavioral Medicine program, the Benson-Henry Institute for Mind Body Medicine, the MGH Cancer Center, and the division of general medicine at Beth Israel Deaconess Medical Center. Dr. Hall’s research examines how medical patients experience and cope with uncertainty and stress arising from cancer and other chronic illnesses. He is currently testing a multimodal mind-body intervention to help ease fear of cancer recurrence.
Read more about Daniel L. Hall, PhD
photo of Florencia Halperin, MD

Florencia Halperin, MD


Florencia Halperin, MD, is the co-founder and Co-Director of the Center for Weight Management and Metabolic Surgery at Brigham and Women’s Hospital, and Chief of Endocrinology at Brigham and Women’s Faulkner Hospital. Her clinical research is focused on the delivery of weight loss interventions, as well as on the metabolic effects of bariatric surgery. Her clinical research is complemented by her clinical practice focused on the management of obesity and diabetes.
Read more about Florencia Halperin, MD
photo of Matthew Hamilton, MD

Matthew Hamilton, MD


Dr. Matthew Hamilton is an associate gastroenterologist at Brigham and Women’s Hospital, and an assistant professor of medicine at Harvard Medical School. He currently serves as the director of the inflammatory bowel disease fellowship and IBD education programs.
Read more about Matthew Hamilton, MD
photo of Syed Moin Hassan, MD

Syed Moin Hassan, MD


Dr. Hassan is currently a sleep medicine fellow at Brigham and Women’s Hospital and Massachusetts General Hospital, and a research fellow at Harvard Medical School. He is also the recipient of the Academic Sleep Pulmonary Integrated Research/Clinical Fellowship (ASPIRE) from the American Thoracic Society. His research interests include sleep-disordered breathing and pulmonary hypertension.
Read more about Syed Moin Hassan, MD
photo of Kathryn Hatch, MD

Kathryn Hatch, MD


Kathryn M. Hatch, MD is the Director of Refractive Surgery at Massachusetts Eye and Ear and the Site Director of Mass. Eye and Ear Waltham. She is an Assistant Professor of Ophthalmology at Harvard Medical School. She is an accomplished surgeon in all-laser refractive surgery techniques including, LASIK and PRK, complex and refractive laser-assisted cataract surgery with intraoperative aberrometry, corneal crosslinking and Intacs (intrastromal corneal ring segments) for keratoconus and post-LASIK ectasia as well as advanced techniques in corneal transplant surgery. Since joining the staff, she has assisted in bringing new technologies to Mass. Eye and Ear including refractive laser-assisted cataract surgery with intraoperative aberrometry, collagen crosslinking, inlays for presbyopia, the Visumax laser (the only laser which performs the small incision lenticule extraction procedure, or SMILE, for the refractive surgical treatment of myopia), and lipiflow for dry eye disease. Dr. Hatch is considered a key opinion leader in the treatment of keratoconus and has been performing collagen crosslinking since 2011. She was an investigator in phase IV clinical trial in which she was performing minimally invasive crosslinking for greater than 5 years. In 2016, she became the first person at Mass. Eye and Ear to perform crosslinking with the FDA-approved technology and is one of the busiest crosslinking specialists in the US. She is embarking in a research project to assist in developing a screening tool for keratoconus and post-LASIK ectasia. Additionally, Dr. Hatch has experience in the treatment of ocular surface disease and dry eye, corneal dystrophies and anterior segment reconstruction. She performs cutting-edge corneal transplantation surgery, including both full thickness penetrating keratoplasty and partial thickness transplant surgery, DSAEK (Descemet Stripping Automated Endothelial Keratoplasty), DMEK (Descemets Membrane Endothelial Keratoplasty), and DALK (Deep Anterior Lamellar Keratectomy). She also performs IEK (Intralase Enabled Keratoplasty) and IE-DALK (Intralase Enabled Deep Anterior Lamellar Keratoplasty) and was the first eye surgeon in New England to perform IE-DALK. Dr. Hatch is an active fellow of the American Academy of Ophthalmology and a diplomat of the American Board of Ophthalmology. She is a member of several organizations including the New England Ophthalmic Society, the Cornea Society, the American Society of Progressive Enterprising Surgeons, the American European College of Ophthalmic Surgeons and the Massachusetts Medical Society. She has been in invited speaker at several regional, national and international meetings. In 2016 and 2017, Dr. Hatch was selected as one of the 300 Premier Innovators in refractive cataract surgery in the United States by Ocular Surgery News.
Read more about Kathryn Hatch, MD
photo of Marissa Hauptman, MD, MPH

Marissa Hauptman, MD, MPH


Dr. Marissa Hauptman is a board-certified pediatrician and associate director of the Pediatric Environmental Health Center; associate director of the Boston Children's Hospital Pediatric and Reproductive Environmental Health Fellowship Program and the Region 1 New England pediatric environmental health specialty unit at Boston Children’s Hospital, where each week she provides multidisciplinary care for children with lead exposure; and an instructor in pediatrics at Harvard Medical School. Dr. Hauptman’s research focuses on using spatial analysis techniques to research and improve environmental and social health disparities in children with chronic diseases. She earned her MD from New York University School of Medicine, and also holds a masters in public health from Brown University.
Read more about Marissa Hauptman, MD, MPH
photo of Chester Hedgepeth, III, MD, PhD

Chester Hedgepeth, III, MD, PhD


Chester M. Hedgepeth, III, MD, PhD, is a cardiovascular specialist at Brigham and Women’s Hospital (BWH) and an instructor in medicine at Harvard Medical School. Dr. Hedgepeth also serves as the executive chief of cardiology for the Care New England Health System, and chief of cardiology at Kent and Memorial Hospitals in Rhode Island.   Dr. Hedgepeth received his medical degree from Perelman School of Medicine at the University of Pennsylvania. He completed an internal medicine residency and fellowships in cardiovascular disease and electrophysiology at BWH. He is board certified in both internal medicine and cardiovascular disease.   Dr. Hedgepeth founded, and currently leads, the BWH/Kent Hospital cardiac telemedicine service, which provides consultative support for Kent Hospital. His clinical and research interests include coronary artery disease, cardiomyopathies, congestive heart failure, cardiac arrhythmia, and the mechanisms of arrhythmic death after myocardial infarction. His research has received support from the National Institutes of Health.
Read more about Chester Hedgepeth, III, MD, PhD
photo of Jeffrey S. Heier, MD

Jeffrey S. Heier, MD


Dr. Jeffrey S. Heier is the director of the retina service and director of retina research at Ophthalmic Consultants of Boston. He is the past president of the Retina Society, a member of the American Society of Retina Specialists executive committee, the past president of the New England Ophthalmological Society, and a member of the Macula Society. He is one of the leading retinal clinical researchers in the country for new treatments in retinal disease. He is a scientific advisor to many biotechnical or pharmaceutical companies, lectures nationally and internationally, and has authored numerous peer-reviewed works. Dr. Heier received his medical degree from Boston University, completed an internship and residency at Fitzsimons Army Medical Center, and a vitreoretinal fellowship at OCB/Tufts School of Medicine. He served as a physician in a combat support hospital in the Persian Gulf War, where he was awarded a Bronze Star.
Read more about Jeffrey S. Heier, MD
photo of Brandi Henson, PsyD

Brandi Henson, PsyD


Brandi S. Henson, PsyD, is an Attending Psychologist in the Department of Psychiatry at Boston Children’s Hospital and a Clinical Instructor of Psychiatry at Harvard Medical School. Her clinical and research interests are in the neurodevelopmental trajectories of children and adolescents with congenital heart disease and associated genetic syndromes.
Read more about Brandi Henson, PsyD
photo of David Hepner, MD, MPH

David Hepner, MD, MPH


David Hepner, MD, MPH, is medical director of the Weiner Center for Preoperative Evaluation at the Brigham and Women’s Hospital, and associate professor of anesthesia at Harvard Medical School. He is an associate faculty member of Ariadne Labs. His clinical and research interests in preoperative assessment, and his vision of a society in the area of preoperative assessment and its impact on surgical outcomes, led him to be one of the cofounders in 2005 of the Society for Perioperative Assessment and Quality Improvement, an international multidisciplinary society. Since then, he has been an active participant in improving surgical outcomes by sharing best practices, promoting research, and enhancing communication among health professionals across multiple disciplines. Dr. Hepner is a founding member of the Emergency Manual Implementation Collaborative, whose goal is to foster the dissemination and effective use of emergency checklists to enhance patient safety. He has helped lead expert panel interactive discussions on progress toward effective use of emergency manuals in hospitals across the country and helped develop an implementation toolkit. Dr. Hepner received his BA from Clark University, his MPH from Harvard School of Public Health, and his MD from Medical College of Wisconsin. His clinical training includes internship in medicine at the Washington University School of Medicine, and residency in anesthesiology and fellowship in obstetric anesthesia at the Hospital of the University of Pennsylvania.
Read more about David Hepner, MD, MPH
photo of Kevin Hill, MD, MHS

Kevin Hill, MD, MHS


Dr. Kevin Hill is director of addiction psychiatry at Beth Israel Deaconess Medical Center, and an associate professor of psychiatry at Harvard Medical School. He earned a master’s in health science at the Robert Wood Johnson Clinical Scholars Program at the Yale School of Medicine. He most commonly treats patients who have problems with alcohol, cannabis, or opioids, and teaches medical students and physicians how to treat patients with addictions. The author of Marijuana: The Unbiased Truth about the World’s Most Popular Weed and coauthor of Medical Cannabis: An Evidence-Based Guide, Dr. Hill’s research interests include the development of medications to treat cannabis use disorder as well as cannabis policy, and he has published widely on these topics in such journals as JAMA, The American Journal of Psychiatry, JAMA Internal Medicine, and Lancet Psychiatry. He serves on the editorial boards of Cannabis and Cannabinoid Research and the American Journal on Addictions.
Read more about Kevin Hill, MD, MHS
photo of Eric Holbrook, MD

Eric Holbrook, MD


Eric H. Holbrook, M.D. graduated from Cornell University with a Bachelors in Science and from the State University of New York Health Science Center in Syracuse with a Masters in Science and a Degree in Medicine. He completed a National Institutes of Health post-doctoral fellowship and residency in otolaryngology at the Medical College of Virginia/Virginia Commonwealth University. He completed further training with a fellowship in Rhinology and Sinus Surgery at the University of Nebraska Medical Center under Dr. Donald Leopold. He has been a member of the full time faculty at the Massachusetts Eye and Ear Infirmary (MEEI) since 2003, is an Associate Professor of Otolaryngology at the Harvard Medical School, and serves as the Chief of the Rhinology Division at MEEI. His principal clinical interests are diseases of the nose and sinuses, chronic rhinosinusitis, endoscopic skull base surgery, and olfactory disorders. His research interests include immunohistochemical characterization of human olfactory tissue, effects of odor exposure on olfactory regeneration, and manipulating human olfactory stem cells for potential restoration of function.
Read more about Eric Holbrook, MD
photo of Sigmund Hough, PhD, ABPP/rp

Sigmund Hough, PhD, ABPP/rp

Contributing Editor

Sigmund Hough, Ph.D., ABPP/rp received his A.B. from Columbia College, Columbia University, M.A. in Developmental Psychology from Columbia University, and Ph.D. in Clinical Psychology from Boston University. Dr. Hough holds ABPP board specialization in Rehabilitation Psychology. He is a Fellow in the National Academy of Neuropsychology, registered as a National Health Care Provider in Psychology, licensed in Massachusetts and Maine. He is a clinical rehabilitation neuropsychologist; Assistant Professor in the Department of Psychiatry, Harvard Medical School and Adjunct Assistant Professor of Psychiatry at Boston University School of Medicine. He has served in the capacity of Clinical Director and Director of Psychological services at private rehabilitation facilities, case reviewer for a nationwide managed care company, and as a clinical service provider in both the public, federal, state and private sector. He has served as Director, Postdoctoral Fellowship Training Program-Boston Consortium in Clinical Psychology. He has conducted nationwide Internship and Postdoctoral Training Site Reviews for the American Psychological Association. He conducts medical facility accreditation site surveys nationwide and internationally for the division of Medical Rehabilitation, CARF. He is an AASECT Certified Sex Therapist and Editor-in-Chief of the international journal Sexuality and Disability. Recipient of the 2004 Clinical Performance Award from The American Association of Spinal Cord Injury Psychologists and Social Workers and the 2005 Award for Excellence in Postdoctoral Training from The Association of Psychology Postdoctoral and Internship Centers (APPIC). As the Past Vice President of the Academy of Spinal Cord Injury Professionals, he currently serves on the Board of Directors.
Read more about Sigmund Hough, PhD, ABPP/rp
photo of Michael Hsu, MD

Michael Hsu, MD

Guest Contributor

Dr. Michael Hsu is a resident psychiatrist and is currently the chief resident of outpatient psychiatry at Brigham and Women's Hospital, a teaching hospital of Harvard Medical School. After graduating from the University of Pennsylvania with degrees in business and computational biology, he worked at a global health care consulting firm before completing his medical degree at Johns Hopkins School of Medicine. He was awarded the 2021–2022 American Psychiatric Association/Substance Abuse and Mental Health Administration Substance Abuse Minority Fellowship, and the 2020 John Renner Travel Award by the American Academy of Addiction Psychiatry. He is passionate about healthcare equity and holistic/integrative approaches to mental health care, and has written and presented about internet gaming disorder, healthcare equity in addiction treatment, cannabis, and digital psychiatry. Following residency, he will pursue a one-year fellowship in addiction psychiatry at Emory University.
Read more about Michael Hsu, MD
photo of Frank Hu, MD, MPH, PhD

Frank Hu, MD, MPH, PhD


Frank Hu, MD, MPH, PhD, is the Fredrick J. Stare Professor of Nutrition and Epidemiology and chair of the department of nutrition at the Harvard T.H. Chan School of Public Health. He is also professor of medicine at Harvard Medical School and Brigham and Women’s Hospital. His major research interests include epidemiology and prevention of cardiometabolic diseases through diet and lifestyle; gene-environment interactions and risk of obesity and type 2 diabetes; nutritional metabolomics in type 2 diabetes and cardiovascular disease; and nutrition transition, metabolic phenotypes, and cardiovascular disease in low- and middle-income countries. Dr. Hu serves as director of the Dietary Biomarker Development Center at Harvard University. He has published a textbook, Obesity Epidemiology (Oxford University Press), and more than 1,500 peer-reviewed papers. Dr. Hu served on the 2015 Dietary Guidelines Advisory Committee. He has served on the editorial/advisory board of The Lancet Diabetes & Endocrinology, Diabetes Care, and Clinical Chemistry. Dr. Hu was elected to the National Academy of Medicine in 2015.
Read more about Frank Hu, MD, MPH, PhD
photo of Thomas Hübl

Thomas Hübl

Guest Contributor

Thomas Hübl is a renowned teacher, and author of Healing Collective Trauma: A Process for Integrating Our Intergenerational and Cultural Wounds. Since 2002, he has led dialogue and restoration processes around collective trauma with more than 100,000 people worldwide. He has been teaching workshops on trauma-informed approaches, resilience, and mindfulness at Harvard since 2019.
Read more about Thomas Hübl
photo of Kimberly Humphrey, MD, MPH

Kimberly Humphrey, MD, MPH


Dr. Kimberly Humphrey is an emergency physician, a current Fellow in Climate Change and Human Health at Harvard C-CHANGE at Harvard's T.H. Chan School of Public Health, and a visiting scholar at the Harvard FXB Center. Her research focuses on the intersection between climate change and health, particularly community and health system adaptation to climate change impacts, and she is passionately involved with advocacy, education, and policy development through NGOs and government-based roles focused on climate change and health.
Read more about Kimberly Humphrey, MD, MPH
photo of Kristin Hung, MD

Kristin Hung, MD


Dr. Kristin Hung is board-certified in urogynecology and reconstructive pelvic surgery (URPS). She is an attending urogynecologist at Massachusetts General Hospital, and serves as division director of quality and clinical operations and instructor at Harvard Medical School. Dr. Hung treats patients with pelvic organ prolapse and urinary incontinence. She specializes in minimally invasive surgical approaches, including vaginal surgery, traditional laparoscopy, and robotic surgeries. Dr. Hung completed her fellowship in URPS at Massachusetts General Hospital and her residency in OB/GYN at Beth Israel Deaconess Medical Center, both in Boston. She obtained her medical degree from the University of Michigan and graduated magna cum laude from Harvard College with a bachelor's in history and science. Dr. Hung is a member of the American Urogynecologic Society and serves on its diversity, equity, and inclusion committee. Her research focuses on shared decision-making tools to improve patient care and outcomes, and health disparities in the treatment of pelvic floor conditions.
Read more about Kristin Hung, MD
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