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Charles Andrew Czeisler, MD, PhD, FRCP
Senior Physician, Brigham and Women's Hospital
Frank Baldino, Jr., Ph.D. Professor of Sleep Medicine, Harvard Medical School

Brigham and Women's Hospital
Department of Medicine
Sleep and Circadian Disorders
75 Francis Street
Boston, MA 02115

Research Location: Boston Lying-In

Research Email:

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Research Narrative:
My laboratory research is focused on understanding the neurobiology of the human circadian pacemaker, located in the suprachiasmatic nucleus (SCN) of the hypothalamus, and its interaction with the sleep homeostat, and on applying that knowledge to clinical medicine and occupational health. We are examining the role of the pineal hormone melatonin in the organization of sleep and circadian rhythms. We are investigating the physiological mechanism underlying photic resetting of the human circadian pacemaker, having shown that some blind people without sight can retain normal circadian responsiveness to light. We are now investigating how the timing, duration, intensity and wavelength of light affects its circadian resetting capacity, which is mediated through intrinsically photosensitive retinal ganglion cells containing the novel photopigment melanopsin. Current research is aimed at functional determination of the photoreceptor(s) responsible for circadian vision in humans, on adaptation of circadian photoreceptors and on the after-effects of entrainment on circadian period in humans. We are investigating how circadian and homeostatic processes interact to regulate sleep and neurobiological function during wakefulness. Other ongoing research in the lab includes examining novel wakefulness- and sleep-promoting countermeasures, the effect of exercise on the circadian pacemaker, fMRI of the sleep deprived brain, the influence of aging on sleep and circadian rhythms, the influence of chronic sleep restriction on human performance, the influence of space flight on sleep and circadian rhythms and the application of our research to night workers-including medical residents and police-through the work of the Sleep Matters Initiative at Brigham Health.

Stanford Medical School, 1981, MD
Stanford University, 1978, PhD
Harvard College, 1974, AB

2019 J.E. Wallace Sterling Lifetime Achievement Award in Medicine, Stanford University School of Medicine Alumni Association
2018 Green Cross for Safety Innovation Award, National Safety Council
2014 Johnson Space Center Director's Innovation Award, NASA
2010 Elected as Member, International Academy of Astronautics
2010 Elected as Member, National Academy of Medicine
2019 Bernese Sleep Award University of Bern, Bern, Switzerland
2019 Peter C. Farrell Prize in Sleep Medicine, Harvard Medical School Division of Sleep Medicine

Jeanne F. Duffy, Ph.D., Brigham and Women's Hospital, Scientific Collaborator

Frank A.J.L. Scheer, PhD, Brigham and Women's Hospital, Scientific Collaborator

Laura K. Barger, PhD, Brigham and Women's Hospital, Scientific Collaborator

Shanthakumar M.W. Rajaratnam, PhD, Monash University, Scientific Collaborator

Steven W. Lockley, PhD, Brigham and Women's Hospital, Scientific Collaborator

Stuart F. Quan, MD, Brigham and Women's Hospital, Scientific Collaborator

Christopher P. Landrigan, MD, MPH, Boston Children's Hospital, Scientific Collaborator

Elizabeth B. Klerman, MD, PhD, Massachusetts General Hospital, Scientific Collaborator

Shadab A. Rahman, PhD, Brigham and Women's Hospital, Scientific Collaborator

Melissa A. St. Hilaire, PhD, Brigham and Women's Hospital, Scientific Collaborator

Courses Taught:
1982-present, Harvard College, Sleep and Circadian Clocks: from Biology to Public Health, The impact of the brain's circadian clock on sleep becomes evident when we travel across time zones or shift our sleep on weekends. How does this clock work? How does light from a tablet or smartphone affect our biology? What is the best time for sleep? What about naps? This course will explore the neurobiology of the brain's circadian clock that regulates the timing and structure of sleep, its interaction with the periodic environment, and the consequences of circadian disruption in our 24/7 society on health, performance and safety.

2019-2020, Harvard College, General Education 1038: Sleep, What is sleep? Why do we sleep? Why don't we sleep? How much sleep do you need? What are circadian rhythms? How do technology and culture impact sleep? This course will explore the role of sleep and circadian timing in maintaining health, improving performance and enhancing safety. We will evaluate the causes and consequences of the epidemic of sleep disorders and deficiency in our society, with particular attention to impacts on brain (learning and memory, mood and cognition) and body (appetite and metabolism, hormones and heart) functions. Personal and public policy approaches to issues such as drowsy students, drowsy drivers and drowsy doctors will be addressed.

Additional News:

Publications (Pulled from Harvard Catalyst Profiles):

1. Barger LK, Sullivan JP, Blackwell T, O'Brien CS, St Hilaire MA, Rahman SA, Phillips AJK, Qadri S, Wright KP, Segar JL, McGuire JK, Vitiello MV, de la Iglesia HO, Poynter SE, Yu PL, Zee P, Sanderson AL, Halbower AC, Lockley SW, Landrigan CP, Stone KL, Czeisler CA. Effects on resident work hours, sleep duration, and work experience in a randomized order safety trial evaluating resident-physician schedules (ROSTERS). Sleep. 2019 Aug 01; 42(8).

2. Kronauer RE, St Hilaire MA, Rahman SA, Czeisler CA, Klerman EB. An Exploration of the Temporal Dynamics of Circadian Resetting Responses to Short- and Long-Duration Light Exposures: Cross-Species Consistencies and Differences. J Biol Rhythms. 2019 Aug 01; 748730419862702.

3. Landrigan CP, Czeisler CA. Patient Safety under Flexible and Standard Duty-Hour Rules. N Engl J Med. 2019 06 13; 380(24):2379-2380.

4. Wolkow AP, Barger LK, O'Brien CS, Sullivan JP, Qadri S, Lockley SW, Czeisler CA, Rajaratnam SMW. Associations between sleep disturbances, mental health outcomes and burnout in firefighters, and the mediating role of sleep during overnight work: A cross-sectional study. J Sleep Res. 2019 May 26; e12869.

5. McHill AW, Hull JT, Cohen DA, Wang W, Czeisler CA, Klerman EB. Chronic sleep restriction greatly magnifies performance decrements immediately after awakening. Sleep. 2019 May 01; 42(5).

6. St Hilaire MA, Anderson C, Anwar J, Sullivan JP, Cade BE, Flynn-Evans EE, Czeisler CA, Lockley SW. Brief (<4 hr) sleep episodes are insufficient for restoring performance in first-year resident physicians working overnight extended-duration work shifts. Sleep. 2019 May 01; 42(5).

7. Robbins R, Grandner MA, Buxton OM, Hale L, Buysse DJ, Knutson KL, Patel SR, Troxel WM, Youngstedt SD, Czeisler CA, Jean-Louis G. Sleep myths: an expert-led study to identify false beliefs about sleep that impinge upon population sleep health practices. Sleep Health. 2019 Aug; 5(4):409-417.

8. Chang AM, Duffy JF, Buxton OM, Lane JM, Aeschbach D, Anderson C, Bjonnes AC, Cain SW, Cohen DA, Frayling TM, Gooley JJ, Jones SE, Klerman EB, Lockley SW, Munch M, Rajaratnam SMW, Rueger M, Rutter MK, Santhi N, Scheuermaier K, Van Reen E, Weedon MN, Czeisler CA, Scheer FAJL, Saxena R. Chronotype Genetic Variant in PER2 is Associated with Intrinsic Circadian Period in Humans. Sci Rep. 2019 Mar 29; 9(1):5350.

9. Blackwell T, Kriesel DR, Vittinghoff E, O'Brien CS, Sullivan JP, Viyaran NC, Rahman SA, Lockley SW, Barger LK, Halbower AC, Poynter SE, Wright KP, Yu PL, Zee PC, Landrigan CP, Czeisler CA, Stone KL. Design and recruitment of the randomized order safety trial evaluating resident-physician schedules (ROSTERS) study. Contemp Clin Trials. 2019 May; 80:22-33.

10. McHill AW, Czeisler CA, Phillips AJK, Keating L, Barger LK, Garaulet M, Scheer FAJL, Klerman EB. Caloric and Macronutrient Intake Differ with Circadian Phase and between Lean and Overweight Young Adults. Nutrients. 2019 03 11; 11(3).