Current Research

It is known that many blind children and adults have difficulty sleeping. We know that this is often due to abnormalities in the body's internal clock, located in a part of the brain called the hypothalamus. The body clocks of sighted people are reset each day by the daily rising and setting of the sun. Natural sunlight is important for keeping the natural body rhythms of most sighted people on a 24-hour schedule. Some blind people may have abnormally timed rhythms because they have little or no light perception. These individuals sometimes have natural body rhythms that free-run, meaning that their natural body rhythms drift each day, which can cause sleep and activity problems.  This is similar to the jet lag that some people experience when they travel.


Currently Recruiting

Research Study of Melatonin Rhythms in Blind Individuals:

The Sleep and Mood Disorders Laboratory at Oregon Health & Science University (OHSU) is seeking blind individuals with no light perception to screen for participation in our research study. 

The goal of our study is to investigate the hormone melatonin and its potential benefits as a treatment for the nighttime sleep difficulties and daytime sleepiness frequently experienced by blind individuals.  This study is looking for blind individuals ages 18 to 100 years.

The study requires frequent saliva collection periods, which will be done by the participant at their home or workplace.  Most collection periods will last for 26 hours, and they will usually be about 2 to 4 weeks apart.  Although no specific time commitment will be required, participants may be invited to continue collections for years.  Participants may be required to take a daily capsule of either melatonin or placebo.  All tests are performed at no charge to the participants.  Participants will be compensated for each saliva collection, and shipping materials and postage are provided free of charge. 

For more information, please contact Joshua Tutek at 503-494-7961, toll free at 1-866-424-6060, or through e-mail at

OHSU IRB# 1029
protocol approved: 02-17-2006

Currently Recruiting

Circadian Studies in Young Blind Children and Adolescents

Are you the parent or friend of a blind child or young adult? Then you may be interested in an NIH-funded, national research opportunity through Oregon Health & Science University.


The Sleep and Mood Disorders Laboratory is seeking participants for circadian rhythm studies, or studies of the internal body clock.

The primary goal of this study is to learn more about irregular body rhythms in blind youth that keep them awake at night or cause them difficulty staying alert during the day. Secondarily, we hope to confirm that melatonin can be used to adjust irregular body rhythms in children, as it does in adults.  

We are looking for blind youth between the ages of 5 and 20 with no light perception, both with and without sleep difficulties.

All participation in this study can be done from home and may include wearing an activity monitor, keeping a sleep journal, periodic saliva collections, and potentially taking melatonin tablets. Participation can take place from anywhere in the country, and all costs will be covered by the investigators. Participants will be compensated for their time.

For more information please email us at, call us at 503-494-1402 or toll-free at 1-866-424-6060, or visit our website at

Study Brochure


1.   Lewy A.J., Emens J., Lefler B.J., Koenig A.R., Yuhas K., Johnson K.P. and Giger P.T. (2004) Melatonin-induced phase delays of the human circadian pacemaker. Sleep (Abstract Supplement) 27:A79.
2.   Lewy A., Lefler B., Yuhas K., Hasler B., Bernert R. and Emens J. (2004) The "sweet spot" for the plasma dim light melatonin onset for winter depressives treated with low-dose daytime melatonin: support for the phase shift hypothesis (PSH). Neuropsychopharmacology 29(1):S103-S104.
3.   Emens J.S., Lewy A.J., Lefler B.J. and Sack R.L. (2005) Relative coordination to unknown “weak zeitgebers” in free-running blind individuals. J. Biol. Rhyth. 20(2):159-167.
4.   Emens J., Lewy A.J., Lefler B.J., Yuhas K., Koenig A.R., Johnson K.P. and Giger P.T. (2005) Relative coordination to unknown “weak zeitgebers” influences lowest entraining dose of exogenous melatonin. Sleep (Abstract Supplement) 28:A69.
5.   Lewy A., Emens J., Lefler B. and Bauer V. (2005) In winter depression (SAD), the sweet spot for the 10 pg/ml plasma dim light melatonin onset (DLMO) is six hours before mid-sleep. Neuropsychopharmacology 30(1):S62-S63.
6.   Lewy A.J., Emens J.S., Lefler B.J., Yuhas K. and Jackman A.R. (2005) Melatonin entrains free-running blind people according to a physiological dose response curve. Chronobiol. Int. 22(6):1093-1106.
7. Lewy A., Emens J., Jackman A. and Yuhas K. (2006) Circadian uses of melatonin in humans. Chronobiology Int. 23(1-2): 403-412.
8. Lewy A.J., Lefler B.J. Emens, J.S. and Bauer V.K. (2006). The circadian basis of winter depression. Proc. Natl. Acad. Sciences 103(19): 7414-7419.
9. Lewy, A., Arntz, D. L., Rough, J. N., Johnson, K. P., Emens, J. S., Kinzie, M. J., Songer, J. B., Yuhas, K., Brick, C. and Bussell, C. A. (2006). Developmental aspects of entrained vs. free-running circadian rhythms. Neuropsychopharmacology (Abstract Supplement) 31(12): S81-2.
10. Lewy, A., Current Understanding and Future Implications of the Circadian Uses of Melatonin, a Neurohormone Discovered by Aaron B. Lerner. Journal of Investigative Dermatology, 2007. 127: p. 2082-2085.
11.   Lewy, A., J. Rough, J. Songer, N. Mishra, K. Yuhas, and J. Emens, The phase shift hypothesis for the circadian component of winter depression. Dialogues in Clinical Neuroscience, 2007. 9: p. 291-300.
12.    Emens, J., Rough, J., Arntz, D., Lewy, A. , Circadian Misalignment Correlates With Symptom Severity in Non-Seasonal Depression. Sleep (Abstract Supplement) 2008. 31: p. A314.
13.    Lewy, A., The circadian function and therapeutic potential of melatonin in humans. Encyclopedia of neuroscience, 2008.
14.    Emens, J., A.J. Lewy, J.N. Rough, and J.B. Songer, Sub-Clinical Dysphoria Correlates with Phase-Delayed Circadian Misalignment in Healthy Individuals. Sleep, 2009. 32(1090): p. A355.
15.    Emens, J.S., A.J. Lewy, M.J. Kinzie, D. Arntz, and J. Rough, Circadian misalignment in major depressive disorder. Psychiatry Research, 2009. 168(3): p. 259-261.
16.    Emens, J.S., A.J. Lewy, J.N. Rough, and J.B. Songer, Sub-Clinical Dysphoria Correlates with Phase-Delayed Circadian Misalignment in Healthy Individuals. Sleep, 2009. 32: p. A355-356.
17.    Lewy, A., J. Emens, J. Songer, N. Sims, A. Laurie, S. Fiala, and A. Buti, Winter Depression: Integrating mood, circadian rhythms, and the sleep/wake and light/dark cycles into a bio-psycho-social-environmental model. Sleep Medicine Clinics, 2009. 4(2): p. 285-299.