Research

Light therapy and light deficiency conditions such as Winter Blues, Seasonal Affective Disorder (SAD), Jet Lag and Shift Work Disorder have been extensively studied and researched over the past three decades. Following is a sampling of the findings and their sources.

Effectiveness and Safety of Light Therapy and Light Visors

Winter Blues

Prevalence of Winter Blues

Winter Blues Symptoms and Onset

Jet Lag

Shift Work

Seniors

Effectiveness and Safety of Light Therapy and Light Visors

Light therapy is an effective treatment for light deficiency disorders like the Winter Blues, sometimes in conjunction with pharmaceuticals.

Lam, R, Levitt, A, Levitan, R et al, The Can-SAD Study: A randomized Controlled Trial of the Effectiveness of Light Therapy and Fluoxetine in Patients with Winter Seasonal Affective Disorder, Am J Psychiatry 163:5, May 2006, page 805, 806, 810, and 811.

A study conducted by Lam, Levitt et al; The Can-SAD Study, compared efficacy of light therapy versus fluoxetine treatments with patients with SAD and showed “overall improvement with time, with no differences between treatments…this study supports the effectiveness and tolerability of both treatments for seasonal affective disorder.”

That study also says “light therapy and fluoxetine are comparably effective treatments for patients with seasonal affective disorder, although light treatment may have a slightly faster onset of effect and slightly fewer treatment-emergent adverse effects.”

http://www.ncbi.nlm.nih.gov/pubmed/16648320
http://www.ncbi.nlm.nih.gov/

Gallin, P, Terman, M et al, Ophthalmologic Examination of Patients with Seasonal Affective Disorder, Before and After Bright Light Therapy, American Journal of Ophthalmology, 119, pages 202-210.

Gallin, Terman et al concluded that “Light therapy yields about 75% clinical remissions.”

http://www.chronotherapeutics.org/docs/other/Gallin%201995.pdf
http://www.chronotherapeutics.org/

Light therapy has be prescribed and used for years for treating symptoms of SAD and S-SAD, and general winter blues

Kripke, D, Light treatment for nonseasonal depression: speed, efficacy, and combined treatment, Journal of Affective Disorders 49, 1998, pages 109-117.

“Bright light treatment for winter depression is recognized in the Clinical Practice Guidelines issued by the U.S. Department of Health and Human Services (Depression Guideline Panel, 1993). The American Psychiatric Association’s Treatment of Psychiatric Disorders also endorsed bright light treatment (Rosenthal, 1995).” From Kripke, “Light treatment for nonseasonal depression”. 1997

http://www.sciencedirect.com/science/article/pii/S0165032798000056
http://www.sciencedirect.com/

Saeed, S. Atezaz, M.D and Bruce, Timothy J, PhD., Seasonal Affective Disorders, American Family Physician, March 1998, page 1.

“…the established effectiveness of light therapy in patients with winter depression supports the usefulness of assessment for this seasonal pattern and consideration of light therapy as an option in addition to existing treatment choices”. AFP, Seasonal Affective Disorders, Saeed and Bruce, University of Illinois, Peoria. 1998

http://www.aafp.org/afp/1998/0315/p1340.html
http://www.aafp.org/

Many people abandon their treatments with traditional Light Boxes early because of inconvenience, importability, and the need to stay in front of them for long periods of time

Avery, D, Eder, D, Bolte, MA et al, Dawn Simulation and Bright Light in the Treatment of SAD: A Controlled Study, Society of Biological Psychiatry, 2001; 50:205-216, page 205.

Although bright light therapy is effective, 69% of SAD patients complain of the inconvenience of finding time to sit in front of the bright light (Oren et al 1991). As many as 19% of SAD patients stop bright light treatment because of inconvenience (Schwartz et al 1996). From Avery et al, 2001 “Dawn simulation and Bright Light in the Treatment of SAD: A Controlled Study”.

http://www.ncbi.nlm.nih.gov/pubmed/11513820
http://www.ncbi.nlm.nih.gov/

Studies show that differences in intensity and light colour have shown little difference in efficacy of light therapy treatment and that white light and red light are similarly efficacious

Teicher, M, Glod, C, Oren, D et al, The Phototherapy Light Visor: More to it than Meets the Eye, Am J Psychiatry 152:8 August 1995, page 1201.

A study conducted by Teicher, Glod, Oren, et al, The Phototherapy Light Visor: More to it than Meets the Eye concludes that “therapeutic outcome [of light therapy] appears to have no direct relationship to intensity (from 30 lux to 6,000 lux), colour (red vs. white), or duration” and that “visor appears to be better than early placebos and at least as effective as a 30-minute treatment with a 2,500-lux light box.

http://www.ncbi.nlm.nih.gov/pubmed/7625470
http://www.ncbi.nlm.nih.gov/

Joffe, R, Moul, D, Lam, R, Levitt, A et al, Light Visor Treatment for Seasonal Affective Disorder: A MultiCenter Study, Psychiatry Research, 46:29-30, 1993, page 29.

Joffe, Moul, Lam, Levitt et al, Light Visor Treatment for seasonal Affective Disorder: A Multicenter Study conducted a study comparing light therapy delivered by visor at three intensities of light (60, 600, and 3500 lux) and found no significant difference in antidepressant efficacy of the three intensities of light.

Moul et al found in their multicenter study of light visor treatment that “there was no significant difference in efficacy of a medium light intensity (600 lux) and a high light intensity (7,000 lux) visor treatment”.

http://www.sciencedirect.com/science/article/pii/0165178193900052
http://www.sciencedirect.com/

Meesters, Y, Beersma, D, Bouhuys, A, and van den Hoofdakker, R, Prophylactic Treatment of Seasonal Affective Disorder (SAD) by Using Light Visors: Bright White or Infrared Light, Society of Biological Psychiatry, 1999.

Meesters, Beersma et al, in Prophylactic Treatment of SAD by using Light Visors: Bright White or Infrared Light?” found that “a light visor emitting infrared light seems to provide at least as much protection as a light visor emitting bright light”.

http://cbn.eldoc.ub.rug.nl/FILES/root/1999/BiolPsychiatMeesters/1999BiolPsychiatMeesters.pdf
http://cbn.eldoc.ub.rug.nl/

Studies show that light therapy delivered via a Head Mounted Unit (HMU) is safe and effective.

Levitt, A, Presented by Dr Anthony Levitt, M.D. R.R.C.P.(C) at the Canadian Psychiatric Association Conference, Montreal, P.Q. September 1992.

Dr Anthony Levitt concluded at the Canadian Psychiatric Association Conference in 1992, that “… (light therapy) when delivered using LED light from a light visor has equivalent efficacy as compared with previously studied light units”.

http://www.nyx.net/~lpuls/hliabs.html
http://www.nyx.net/

Meesters, Y, Beersma, D, Bouhuys, A, and van den Hoofdakker, R, Prophylactic Treatment of Seasonal Affective Disorder (SAD) by Using Light Visors: Bright White or Infrared Light, Society of Biological Psychiatry, 1999.

Meesters, Beersma et al, in Prophylactic Treatment of SAD by using Light Visors: Bright White or Infrared Light?” found that “this study demonstrates that SAD patients wearing a light-emitting visor in winter develop fewer symptoms than waiting-list control subjects”

http://cbn.eldoc.ub.rug.nl/FILES/root/1999/BiolPsychiatMeesters/1999BiolPsychiatMeesters.pdf
http://cbn.eldoc.ub.rug.nl/

Gallin, P, Terman, M et al, Ophthalmologic Examination of Patients with Seasonal Affective Disorder, Before and After Bright Light Therapy, American Journal of Ophthalmology, 119, pages 202-210.

Gallin et al also concluded that “no ocular changes were detected after short-term treatment. Long-term treatment…also resulted in no ocular abnormalities”.

http://chronotherapeutics.org/docs/other/Gallin%201995.pdf
http://chronotherapeutics.org/

30 minutes a day is enough to see results

Joffe, R, Moul, D, Lam, R, Levitt, A et al, Light Visor Treatment for Seasonal Affective Disorder: A Multicenter Study, Psychiatry Research, 46:29-30, 1993, pages 31, 33,& 34.

Joffe, Moul, Lam et al administered light therapy at 60, 600, and 3500 lux “for 1/2 hour daily for a period of 2 weeks.

http://www.sciencedirect.com/science/article/pii/0165178193900052
http://www.sciencedirect.com/

Saeed, S. Atezaz, M.D and Bruce, Timothy J, PhD., Seasonal Affective Disorders, American Family Physician, March 1998, page 1.

“The patient should start with a single 10-15 minute session per day, gradually increasing the session’s duration to 30-45 minutes.” From AFP, Seasonal Affective Disorders, Saeed and Bruce, University of Illinois, Peoria. 1998.

http://www.aafp.org/afp/1998/0315/p1340.html
http://www.aafp.org/

Gallin, P, Terman, M et al, Ophthalmologic Examination of Patients with Seasonal Affective Disorder, Before and After Bright Light Therapy, American Journal of Ophthalmology, 119, pages 202-210.

A study conducted by Gallin, Termen et al, “administered light therapy at 10,000 lux for 30 minutes daily for two weeks, followed by a withdrawal period of approximately ten days before switching to treatment at the alternate time of the day”. Their study concluded that “Light therapy yields about 75% clinical remissions. It is effective as an antidepressant and appears safe for the eyes”.

http://chronotherapeutics.org/docs/other/Gallin%201995.pdf
http://chronotherapeutics.org/

Teicher, M, Glod, C, Oren, D et al, The Phototherapy Light Visor: More to it than Meets the Eye, Am J Psychiatry 152:8 August 1995, pages 1197 and 1201.

A study conducted by Teicher, Glod, Oren et al, administered “over a two week treatment period, 30 minutes of morning phototherapy with a light visor that emitted either a dim (30 lux) or a bright (600-lux) white light.” They found that “therapeutic outcome appears to have no direct relationship to intensity (from 30 lux to 6,000 lux), colour (red versus white), or duration (30-60 minutes)” and “appears at least as effective as a 30 minute treatment with a 2,500 lux light box”.

http://ajp.psychiatryonline.org/article.aspx?Volume=152&page=1197&journalID=13
http://ajp.psychiatryonline.org/

Improvements to symptoms of the winter blues can often be seen after just one to two weeks of light therapy

Saeed, S. Atezaz, M.D and Bruce, Timothy J, PhD., Seasonal Affective Disorders, American Family Physician, March 1998, page 1.

“Although some patients show an immediate benefit from light therapy, most take two to four days to experience a sustained antidepressant response.” From AFP, Seasonal Affective Disorders, Saeed and Bruce, University of Illinois, Peoria. 1998

http://www.aafp.org/afp/1998/0315/p1340.html
http://www.aafp.org/

Winter Blues

Prevalence of Winter Blues

Up to 20%-25% of North Americans suffer from SAD or Sub-Syndromal SAD (S-Sad)

Saeed, S. Atezaz, M.D and Bruce, Timothy J, PhD., Seasonal Affective Disorders, American Family Physician, March 1998, page 2.

“Surveys estimate that 4 to 6 percent of the general population experience winter depression, and another 10 to 20 percent have sub-syndromal features. Women with SAD outnumber men four to one. The average age of onset is approximately 23 years of age.”

http://www.aafp.org/afp/980315ap/saeed.html
http://www.aafp.org/

Avery, D, Kizer, D, Bolte, M and Hellekson, C, Bright light therapy of subsyndromal seasonal affective disorder in the workplace, Acta Psychiatrica Scandinavica, March 2001. Page 268.

Subsyndromal Seasonal Affective Disorder is a milder form of SAD experienced by an estimated 14.3% (vs. 6.1% SAD) of the U.S. population. Avery, D. H.; Kizer D, Bolte MA, Hellekson C (2001).

http://www.ncbi.nlm.nih.gov/pubmed/11328240
http://www.ncbi.nlm.nih.gov/

In regions with higher latitudes the prevalence of SAD or S-SAD sufferers is higher

Said, M, Seasonal Affective Disorder, University of Liverpool, UK, Jan 2001, page 4.

Table 4: The prevalence of SAD and S-SAD in a survey carried out in the USA

Location   Latitude (north)         SAD (%)  SAD + S-SAD (%)
New Hampshire             43°             9.7            20.7
New York             40°             4.7            17.1
Maryland             39°             6.3            16.7
Florida             27°             1.4              4.0

http://priory.com/psych/SAD.htm
http://priory.com/
Johnson, Roger and Somes, Sandra, NIMH, JAMA Shed Light on Seasonal Affective Disorder, February 1994.

“The prevalence of SAD in the United States has been found to increase with increasing latitude.” NIMH, JAMA Shed light on Seasonal Affective Disorder, Roger Johnson and Sandra Somers, Feb 1, 1994 Psychiatric Times.

http://www.psychiatrictimes.com/display/article/10168/50226
http://www.psychiatrictimes.com/

Some studies suggest that even as many as 90% of people living in higher latitudes experience some form of the Winter Blues

Kasper, S, Wehr, T, Bartko, J, Gaist, P and Rosenthal, N, Epidemiological Findings of Seasonal Changes in Mood and Behaviour, Arch Gen Psychiatry – Vol 46, September 1989.

“Patterns of seasonal changes in mood and behavior in Montgomery County, Maryland, were evaluated in randomly selected household samples by lay interviewers using a telephone version of the Seasonal Pattern Assessment Questionnaire. The method for selecting the sample unit was random-digit dialing. We found that 92% of the survey subjects noticed seasonal changes of mood and behavior to varying degrees. For 27% of the sample seasonal changes were a problem and 4.3% to 10% of subjects, depending on the case-finding definition, rated a degree of seasonal impairment equivalent to that of patients with seasonal affective disorder. The seasonal pattern of “feeling worst” exhibited a bimodal distribution with a greater winter and a substantially lower summer peak (ratio, 4.5:1). Younger women who have a problem with seasonal changes and who feel worse on short days tended to exhibit the highest seasonality scores. It is apparent from our study that seasonal affective disorder represents the extreme end of the spectrum of seasonality that affects a large percentage of the general population.”

http://www.ncbi.nlm.nih.gov/pubmed/2789026
http://www.ncbi.nlm.nih.gov/

More women than men suffer from SAD and the Winter Blues

Leibenluft, E, Hardin, T, and Rosenthal, N, Gender Differences in Seasonal Affective Disorder, National Institute of Mental Health, Besthesda, MD, Sept 1994.

In most samples of patients with seasonal affective disorder (SAD), women outnumber men by more than three to one (Oren and Rosenthal, 1992). Furthermore, epidemiological data suggest that SAD is more prevalent in women than men during the reproductive years, from puberty (Pleeter et al., unpublished manuscript) until the sixth decade (Kasper et al., 1989). From Gender differences in SAD; Rosenthal, Leibenluft et al, 1995.

http://onlinelibrary.wiley.com/doi/10.1002/depr.3050030104/abstract
http://onlinelibrary.wiley.com/

Rosenthal, N, Sack, D, Gillin, C et al, Seasonal Affective Disorder: A Description of the Syndrome and Preliminary Findings with Light Therapy, Arch Gen Psychiatry, Vol 41, Jan 1984, page 77.

“The far higher ratio that we observed may indicate that some characteristic of women makes them particularly vulnerable to SAD”. From “Seasonal Affective Disorder” Rosenthal, Sack et al, 1984

http://www.ncbi.nlm.nih.gov/pubmed/6581756?tool=bestpractice.bmj.com
http://www.ncbi.nlm.nih.gov/

Johnson, R and Somers, S, NIMH, JAMA Shed Light on Seasonal Affective Disorder, February 1994. Page 1.

“Most (75 percent to 80 percent) of SAD sufferers are women, for whom the illness typically begins in the third decade of life.” NIMH, JAMA Shed light on Seasonal Affective Disorder, Roger Johnson and Sandra Somers, Feb 1, 1994 Psychiatric Times.

http://www.psychiatrictimes.com/display/article/10168/50226
http://www.psychiatrictimes.com/

WinterBlues Symptoms and Onset

Some symptoms of SAD and the Winter Blues are:

    1. Mood disturbances and mild to major depressive episodes
    2. Low energy
    3. Low libido
    4. Weight gain
    5. Poor sleep quality

Saeed, S. Atezaz, M.D and Bruce, Timothy J, PhD., Seasonal Affective Disorders, American Family Physician, March 1998, page 1.

“The most recognized form of seasonal affective disorder, “winter depression,” is characterized by recurrent episodes of depression, hypersomnia, augmented appetite with carbohydrate craving, and weight gain that begin in the autumn and continue through the winter months. ” AFP, Seasonal Affective Disorders, Saeed and Bruce, University of Illinois, Peoria. 1998

http://www.aafp.org/afp/1998/0315/p1340.html
http://www.aafp.org/

Whalen, David, Seasonal Affective Disorder, Canadian Mental Health Association.

“Typical symptoms of the more common winter SAD include increased appetite (particularly carbohydrate-rich and starchy foods), increased sleeping, irritability, forgetfulness, reduced libido, and feelings of inadequacy.” From Seasonal Affective Disorder, David Whalen for the Canadian Mental Health Association.

http://www.cmhanl.ca/pdf/Seasonal%20Affective%20Disorder%20(SAD)2.pdf
http://www.cmhanl.ca/

Johnson, R and Somers, S, NIMH, JAMA Shed Light on Seasonal Affective Disorder, February 1994.

“SAD symptoms in adults include lethargy, fatigue, ravenous appetite, weight gain, carbohydrate craving, withdrawal from relationships, inability to concentrate or focus, problems at work, anxiety, and despair.” NIMH, JAMA Shed light on Seasonal Affective Disorder, Roger Johnson and Sandra Somers, Feb 1, 1994 Psychiatric Times

http://www.psychiatrictimes.com/display/article/10168/50226
http://www.psychiatrictimes.com/

SAD, S-SAD, the Winter Blues and other conditions brought on by light deficiency occur when there are disturbances to our circadian rhythms (our body clocks) brought about by disruptions to our melatonin and serotonin productions (hormones responsible for our moods, hunger, sex drive, and sleeping patterns) as a result of too little exposure to light

Lewy AJ, Lefler BJ, Emens JS, Bauer VK. The circadian basis of winter depression. Proc Natl Acad Sci U S A. 2006 Apr 28.

“Most Seasonal Affective Disorder (SAD) symptoms stem from daily body rhythms that have gone out-of-sync with the sun, a NIMH funded study has found. …Rhythms that have lost their bearings due to winter’s late dawn and early dusk accounted for 65 percent of SAD symptoms; …SAD affects many people in northern latitudes in winter, especially young women, and is usually treated with bright light in the morning. ..The pineal gland, located in the middle of the brain, responds to darkness by secreting melatonin, which re-sets the brain’s central clock and helps the light/dark cycle re-set the sleep/wake cycle and other daily rhythms.” From NIMH website, Science News from 2006 Science Update, May 01, 2006.

http://www.pnas.org/content/103/19/7414.abstract
http://www.pnas.org/

Typically people begin to notice the start of symptoms between the ages of 20 and 50

Whalen, David, Seasonal Affective Disorder, Canadian Mental Health Association.

Rosenthal and his colleagues…have also reported that those aged between 20 and 40 appear to be the most susceptible to SAD (1993). From Seasonal Affective Disorder, David Whalen for the Canadian Mental Health Association

http://www.cmhanl.ca/pdf/Seasonal%20Affective%20Disorder%20(SAD)2.pdf
http://www.cmhanl.ca/

Shift Work

Circadian rhythm disruptions put the health of shift workers at risk

Rüdiger HW. [Health problems due to night shift work and jetlag]. Internist (Berl). 2004 Sep;45(9):1021-5. Klinische Abteilung Arbeitsmedizin, Medizinische Universität Wien. hugo.ruediger@meduniwien.ac.at.

“Work against the biologic clock increases the risks for accidents and may produce health risks as sleeping or gastro-intestinal disorders, depression, cardio-vascular diseases, overweight, and a disturbed sexual activity and fertility. Adaptation to an altered day/night rhythm during night shift work takes more than a week, and even then the time shift is rarely complete. In contrast the duration of time shift is much shorter during a jetlag and is mostly completed after 2-3 days. Therefore, much less health risk is to be expected from jetlag as compared to night shift work. About 15% of all healthy adults are insufficiently adaptable to night shift work. These individuals carry a particularly high health risk, if regularly participating in night shift work.”

http://www.ncbi.nlm.nih.gov/pubmed/15252716
http://www.ncbi.nlm.nih.gov/

Laurie Tarkan. Your eyes may be the windows to a faster aging process. The New York Times, Herald-Tribune (Tuesday, February 21, 2012)

The New York Times reported on February 221, 2012 that people whose circadian rhythms are out of sync, like shift workers, are at greater risk for a number of ailments, including insomnia, heart disease and cancer, and that researchers have discovered that the body clock relies on light to function properly. According to Dr. David Berson, of Brown University in Providence, R.I, the role of synchronizing our circadian rhythms lies with the eye, which detects light through specialized cells and then sends signals to the brain to release the hormones that our body needs to function properly throughout the day.

http://health.heraldtribune.com/2012/02/21/your-eyes-may-be-the-windows-to-a-faster-aging-process/

American Academy of Sleep Medicine (2007, August 1). Rotating Shift Workers Have Lower Levels Of Serotonin. ScienceDaily. Retrieved March 21, 2012.

“People who work rotating shifts have significantly lower levels of serotonin, a hormone and neurotransmitter in the central nervous system believed to play an important role in the regulation of sleep, according to a study published in the August 1st issue of the journal Sleep, authored by Carlos J. Pirola, PhD, of the Universidad de Buenos Aires, Argentina.”

“…In addition to sleep problems, low levels of serotonin are also associated with other conditions such as anger, depression and anxiety. Shift work sleep disorder is a circadian rhythm sleep disorder that occurs due to a work schedule that takes place during the normal sleep period. This schedule requires you to work when your body wants to sleep. Then you have to try to sleep when your body expects to be awake. The timing of when you sleep and wake is much different than what your internal body clock expects.”

“This sleep problem causes you to have trouble sleeping or to be severely tired. It is most often reported due to the night and early-morning shifts. These workers typically sleep one to four hours less than average. They also feel that the quality of their sleep is very poor. They do not feel refreshed when they wake up. This can hinder their performance at work. It can also make them less alert. This can put them at risk of an injury on the job.”

http://www.sciencedaily.com/releases/2007/08/070801091343.htm
http://www.sciencedaily.com/

Blask DE. Melatonin, sleep disturbance and cancer risk. Sleep Medicine Review. 2009 Aug;13(4):257-64. Epub 2008 Dec 17. Laboratory of Chrono-Neuroendocrine Oncology, Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA. dblask@tulane.edu.

“The pineal hormone melatonin is involved in the circadian regulation and facilitation of sleep, the inhibition of cancer development and growth, and the enhancement of immune function. Individuals, such as night shift workers, who are exposed to light at night on a regular basis experience biological rhythm (i.e., circadian) disruption including circadian phase shifts, nocturnal melatonin suppression, and sleep disturbances. Additionally, these individuals are not only immune suppressed, but they are also at an increased risk of developing a number of different types of cancer. There is a reciprocal interaction and regulation between sleep and the immune system quite independent of melatonin. Sleep disturbances can lead to immune suppression and a shift to the predominance in cancer-stimulatory cytokines. Some studies suggest that a shortened duration of nocturnal sleep is associated with a higher risk of breast cancer development. The relative individual contributions of sleep disturbance, circadian disruption due to light at night exposure, and related impairments of melatonin production and immune function to the initiation and promotion of cancer in high-risk individuals such as night shift workers are unknown. The mutual reinforcement of interacting circadian rhythms of melatonin production, the sleep/wake cycle and immune function may indicate a new role for undisturbed, high quality sleep, and perhaps even more importantly, uninterrupted darkness, as a previously unappreciated endogenous mechanism of cancer prevention.”

http://www.ncbi.nlm.nih.gov/pubmed/19095474
http://www.ncbi.nlm.nih.gov/

Light therapy can reset the body clock by realigning circadian rhythms that are disturbed in shift workers

Gooley JJ., Division of Sleep Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. Treatment of circadian rhythm sleep disorders with light, Annals of the Academy of Medicine, Singapore. 2008 Aug;37(8):669-76.

“The human circadian system is normally synchronised with the solar day, insuring that alertness and performance peak during daytime hours and consolidated sleep occurs during the night. In circadian rhythm sleep disorders, the pattern of sleep-wake is misaligned with the patient’s circadian system or the external environment, resulting in insomnia, fatigue, and deterioration in performance. Appropriately-timed exposure to bright light can reset the timing of sleep and wake to the desired times, and improve sleep quality and daytime alertness. The efficacy of bright light therapy, however, is dependent on the time-of-day of the circadian cycle that the light is administered. In this article, we examine the physiological basis for bright light therapy, and we discuss the application of light in the treatment of circadian rhythm sleep disorders including advanced and delayed sleep-phase disorder, free-running disorder (nonentrained type), shift work disorder and jet lag disorder. We review the laboratory and field studies which have established bright light therapy as an effective treatment for sleep-wake and circadian misalignment, and we also provide guidelines for the appropriate timing and safe use of bright light therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/18797560
http://www.ncbi.nlm.nih.gov/

Kolla BP, Auger RR. Jet lag and shift work sleep disorders: how to help reset the internal clock. Cleveland Clinic Journal of Medicine. 2011 Oct;78(10):675-84. doi: 10.3949/ccjm.78a.10083. Mayo Center For Sleep Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.

“Jet lag sleep disorder and shift work sleep disorder are the result of dyssynchrony between the internal clock and the external light-dark cycle, brought on by rapid travel across time zones or by working a nonstandard schedule. Symptoms can be minimized by optimizing the sleep environment, by strategic avoidance of and exposure to light, and also with drug and behavioral therapies.”

http://www.ncbi.nlm.nih.gov/pubmed/21968474
http://www.ncbi.nlm.nih.gov/

Boivin DB, James FO. Light treatment and circadian adaptation to shift work. Industrial Health. 2005 Jan;43(1):34-48. Center for Study and Treatment of Circadian Rhythms, Douglas Hospital Research Center, affiliated to the Department of Psychiatry, McGill University, 6875 LaSalle Boulevard, room F-1127, Montreal, Quebec, H4H 1R3, Canada.

“Work at unconventional hours can have both long and short term consequences. Shift workers are often required to perform their duties at times that are not favoured by the body’s endogenous clock, or circadian pacemaker. A typical night shift worker, for example, may report reductions in alertness and performance during shifts, or significant difficulty attaining sleep of recuperative value in the day, all the while being more likely to develop health complications. The study of circadian physiology has significantly contributed to our current ability to aid the shift worker deal with atypical schedules. We discuss the usefulness of light treatment as a countermeasure for maladaptation to atypical work schedules.”

http://www.ncbi.nlm.nih.gov/pubmed/15732302
http://www.ncbi.nlm.nih.gov/

Bjorvatn B, Stangenes K, Oyane N, Forberg K, Lowden A, Holsten F, Akerstedt T. Randomized placebo-controlled field study of the effects of bright light and melatonin in adaptation to night work. Scandinavian Journal of Work, Environment and Health. 2007 Jun;33(3):204-14. Department of Public Health and Primary Health Care, University of Bergen, Kalfarveien 31, N-5018 Bergen, Norway. bjorn.bjorvatn@isf.uib.no.

“This study evaluated the effects of bright light and melatonin on adaptation to night work on an oil rig in the North Sea.” “Melatonin and bright light modestly improved sleep and sleepiness in this field study. In well-controlled simulated nightwork studies, both melatonin and bright light are more effective in alleviating sleepiness and sleep problems. The less effect in this field study may be due to competing or conflicting factors present in real life or to an inoptimal timing and duration of the treatments.”

http://www.ncbi.nlm.nih.gov/pubmed/17572830
http://www.ncbi.nlm.nih.gov/

Yoon IY, Jeong DU, Kwon KB, Kang SB, Song BG. Bright light exposure at night and light attenuation in the morning improve adaptation of night shift workers. Sleep. 2002 May 1;25(3):351-6. Yong-In Mental Hospital, Republic of Korea.

“With practical applicability in mind, we wanted to observe whether nocturnal alertness, performance, and daytime sleep could be improved by light exposure of tolerable intensity and duration in a real work place. We also evaluated whether attenuating morning light was important in adaptation of real night shift workers. Twelve night shift nurses participated in this study. The study consisted of three different treatment procedures: Room Light (RL), Bright Light (BL), and Bright Light with Sunglasses (BL/S). In RL, room light exposure was given during the night shift and followed by 1 hr exposure to sunlight or 10,000 lux light the next morning (from 08:30 to 09:30). In BL, a 4-hour nocturnal light exposure of 4,000-6,000 lux (from 01:00 to 05:00) was applied and followed by the same morning light exposure as in RL. In BL/S, the same nocturnal light exposure as in BL was done with light attenuation in the morning. Each treatment procedure was continued for 4 days in a repeated measures, cross-over design. Nocturnal alertness was measured by a visual analog scale. Computerized performance tests were done. Daytime sleep was recorded with actigraphy. The most significant overall improvement of sleep was noted in BL/S. BL showed less improvement than BL/S but more than RL. Comparison of nocturnal alertness among the 3 treatments produced similar results: during BL/S, the subjects were most alert, followed by BL and then by RL. Real night shift workers can improve nocturnal alertness and daytime sleep by bright light exposure in their work place. These improvements can be maximized by attenuating morning light on the way home.”

http://www.ncbi.nlm.nih.gov/pubmed/12003167
http://www.ncbi.nlm.nih.gov/

Eastman CI, Boulos Z, Terman M, Campbell SS, Dijk DJ, Lewy AJ. Light treatment for sleep disorders: consensus report. VI. Shift work. Journal of Biological Rhythms. 1995 Jun;10(2):157-64. Biological Rhythms Research Laboratory, Rush-Presbyterian-St. Luke’s Medical Center, Chicago, IL 60612, USA.

“The unhealthy symptoms and many deleterious consequences of shift work can be explained by a mismatch between the work-sleep schedule and the internal circadian rhythms. This mismatch occurs because the 24-h zeitgebers, such as the natural light-dark cycle, keep the circadian rhythms from phase shifting to align with the night-work, day-sleep schedule. This is a review of studies in which the sleep schedule is shifted several hours, as in shift work, and bright light is used to try to phase shift circadian rhythms. Phase shifts can be produced in laboratory studies, when subjects are kept indoors, and faster phase shifting occurs with appropriately timed bright light than with ordinary indoor (dim) light. Bright light field studies, in which subjects live at home, show that the use of artificial nocturnal bright light combined with enforced daytime dark (sleep) periods can phase shift circadian rhythms despite exposure to the conflicting 24-h zeitgebers. So far, the only studies on the use of bright light for real shift workers have been conducted at National Aeronautics and Space Administration (NASA). In general, the bright light studies support the idea that the control of light and dark can be used to overcome many of the problems of shift work. However, despite ongoing practical applications (such as at NASA), much basic research is still needed.”

http://www.ncbi.nlm.nih.gov/pubmed/7632989
http://www.ncbi.nlm.nih.gov/

 Schwartz JR, Roth T. Shift work sleep disorder: burden of illness and approaches to management. Drugs. 2006;66(18):2357-70. Integris Sleep Disorder Center and University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73109, USA.

“More than 6 million Americans work night shifts on a regular or rotating basis. The negative consequences of shift work have been established, and recent evidence suggests that patients with shift work sleep disorder (SWSD) are at increased risk of these consequences and co-morbidities. SWSD is a relatively common but under-recognised, and hence undertreated, condition with potentially serious medical, social, economic and quality-of-life consequences. In addition to increased risk of gastrointestinal and cardiovascular disease, patients with SWSD experience clinically significant excessive sleepiness or insomnia associated with work during normal sleep times, which has important safety implications. A number of studies have evaluated countermeasures or interventions in shift workers; proposed treatments include chronobiotic interventions, such as light exposure, melatonin, hypnotic agents, caffeine and CNS stimulants (amphetamine), and the wake-promoting agents modafinil and armodafinil. However, most studies evaluating pharmacological therapies and nonpharmacological interventions simulate night-shift work under conditions that may not accurately reflect real-world activities. Pharmacological and nonpharmacological countermeasures evaluated mostly in simulated laboratory conditions have been shown to improve alertness or sleep in shift workers but have not yet been evaluated in patients with SWSD. To date, three randomised, double-blind clinical studies have evaluated pharmacological therapies in patients with SWSD. These studies showed that modafinil and armodafinil significantly improve the ability to sustain wakefulness during waking activities (e.g. working, driving), overall clinical condition, and sustained attention or memory in patients with SWSD. In conclusion, SWSD is a common condition that remains under-recognised and undertreated. Further research is needed to evaluate different treatment approaches for this condition, to clarify the substantial health and economic consequences of SWSD, and to determine the potential for interventions or treatments to reduce the negative consequences of this condition.”

http://www.ncbi.nlm.nih.gov/pubmed/17181377
http://www.ncbi.nlm.nih.gov/

Jet Lag

Circadian rhythm disruptions from jet lag can negatively affect cognitive performance, and mental and physical health

Reid KJ, McGee-Koch LL, Zee PC. Cognition in circadian rhythm sleep disorders. Progress in Brain Research. 2011;190:3-20. Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA. k-reid@northwestern.edu.

“Circadian rhythms in physiology and behavior exist in all living organisms, from cells to humans. The most evident rhythms are the recurrent cycles of sleep and wake as well as changes in alertness and cognitive performance across the 24h. Clearly, sleep pressure can exert a strong influence on cognitive performance, but the influence of circadian modulation of alertness and cognitive function is evident even when the pressure for sleep is high. Circadian rhythms also influence more complex cognitive tasks, such as selective attention and executive function, which are important for work performance and safety. The circadian timekeeping system also ensures that circadian rhythms are appropriately synchronized to the external physical environment and work and social schedules. Circadian misalignment is the basis for all circadian rhythm sleep disorders. These disorders are often associated with impairments of cognitive performance that can have adverse effects on school and work performance, overall quality of life, and safety.”

http://www.ncbi.nlm.nih.gov/pubmed/21531242
http://www.ncbi.nlm.nih.gov/

Katz G, Durst R, Zislin Y, Barel Y, Knobler HY. Psychiatric aspects of jet lag: review and hypothesis. Medical Hypotheses. 2001 Jan;56(1):20-3. Kfar Shaul Mental Health Center affiliated with the Hebrew University, Hadassah Medical School, Jerusalem, Israel. Rimona@isdn.net.il.

“Jet lag is a travel-induced circadian rhythm phenomenon that afflicts healthy individuals following long- distance flights through several time zones. The typical jet-lag manifestations – insomnia during local sleep time, day fatigue, reduced concentration, irritability, and exhaustion with mild depression – are attributed to transient desynchronization in the circadian rhythm until the internal biological clock is rephased to the new environmental conditions. There is strong evidence relating affective disorders with circadian rhythm abnormalities. Less convincing suggestions relate jet lag to psychosis. It can be hypothesized that in predisposed individuals jet lag may play a role in triggering exacerbation or even de novo affective disorders. Furthermore, we propose the possibility that psychosis and even schizophrenia can be elicited by jet lag. This outlook gains its support from case studies and some common underlying phase-advanced biological denominators involved in both jet lag sufferers and psychotic patients.”

http://www.ncbi.nlm.nih.gov/pubmed/11133250
http://www.ncbi.nlm.nih.gov/

Cho K, Ennaceur A, Cole JC, Suh CK. Chronic jet lag produces cognitive deficits. The Journal of Neuroscience: the official journal of the Society for Neuroscience. 2000 Mar 15;20(6):RC66. Department of Psychology, University of Durham, Durham, DH1 3LE, United Kingdom. Kei.Cho@bris.ac.uk.

“Traveling across time zones causes disruption to the normal circadian rhythms and social schedules because of travelers’ shift in time. As the endogenous circadian timing system adapts slowly to new time cues, the phase relationship between biological rhythms and external time cues are out of synchronization for a period of time. This disturbance of circadian rhythms has been shown to impair physical and psychological health (Winget et al., 1984). To test the effects of repeated jet lag on mental abilities, airline cabin crew were compared with ground crew. Salivary cortisol was used as a physiological marker for circadian disruption. The cabin crew group, who had a history of repeated jet lag, had significantly higher salivary cortisol levels in an average working day. In addition, this elevated level of cortisol was only seen in the same subjects when the cabin crew were on transmeridian flights but not domestic flights. Cabin crew also exhibited cognitive deficits, possibly in working memory, that became apparent after several years of chronic disruption of circadian rhythms.”

http://www.ncbi.nlm.nih.gov/pubmed/10704520
http://www.ncbi.nlm.nih.gov/

Greene MW. Circadian rhythms and tumor growth. Cancer Letters. 2012 May 28;318(2):115-23. Epub 2012 Jan 15. Bassett Research Institute, Bassett Healthcare Network, One Atwell Road, Cooperstown, NY 13326-1301, USA.

“Hormone secretion, metabolism, and the cell cycle are under rhythmic control. Lack of rhythmic control has been predicted to lead to uncontrolled proliferation and cancer. Consistent with this prediction are findings that circadian disruption by dim light at night or chronic jet lag accelerates tumor growth in desynchronized animals. Circadian controlled factors such as insulin/IGF-1, glucocorticoids, catecholamines, and melatonin have be implicated in controlling tumor growth in the desynchronized animals. Recent attention has focused on the signaling pathways activated by the circadian controlled factors because these pathways hold the potential for the development of novel strategies for cancer prevention and treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/22252116
http://www.ncbi.nlm.nih.gov/

Jet lag has a negative impact on athletic performance

R. Manfredini, F. Manfredini, C. Fersini, and F. Conconi, Circadian rhythms, athletic performance, and jet lag, Br J Sports Med. 1998 June; 32(2): 101–106. (PMCID: PMC1756080)

“Rapid air travel across several time zones exposes the traveller to a shift in his/her internal biological clock. The result is a transient desynchronisation of the circadian rhythm, called jet lag, lasting until the rhythm is rephased to the new environmental conditions. The most commonly experienced symptoms are sleep disorders, difficulties with concentrating, irritability, depression, fatigue, disorientation, loss of appetite, and gastrointestinal disturbance. Apart from the decrements in mental and physical performance directly consequent on such symptoms, competitive athletes are also exposed to the additional negative consequences of a shift from the optimal circadian window of performance.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1756080/
http://www.ncbi.nlm.nih.gov/

Loat CE, Rhodes EC, J.M. Buchanan Exercise Science Laboratory, University of British Columbia, Vancouver, Canada, Jet-lag and human performance, Sports Med. 1989 Oct;8(4):226-38.

“The desynchronisation of an athlete’s physiological and psychological cycles has adverse effects on his/her performance. The primary cause of dysrhythmia in an athlete is jet-lag, which is a rapid displacement across the earth’s time zones and is often experienced while competing in international events and in continental leagues. General symptoms which arise from dysynchronization include malaise, appetite loss, tiredness during the day and disturbed sleep. The specific symptoms resulting from jet-lag are characterised as phase shifts in physiological and psychological cycles. These phase shifts occur in body temperature, ability to mobilise energy substrates, excretion of water and metabolites, arousal levels, sleep/wake cycles and reaction time. The severity of these adverse effects and therefore the time required for resynchronization depends on the ability to preset the bodily rhythms prior to flying, the number of time zones crossed, the direction of flight, the type of individual (introvert/extrovert), age, social interaction and activity, diet plan and prescribed use of chronobiotic drugs.”

http://www.ncbi.nlm.nih.gov/pubmed/2692117
http://www.ncbi.nlm.nih.gov/

Brown, G, M.D. Ph.D., Light, Melatonin and Sleep-Wake Cycle, The Clarke Institute of Psychiatry, Toronto, August 1994, page 345.

“Today it is well established that the pineal gland is a major transducer of photoperiodic information which is converted in the light-dark cycle to a hormonal signal. The pineal hormone melatonin is secreted during the hours of darkness and is low during daylight hours. The pineal is regulated by an endogenous rhythm-generating system located in the suprachiasmatic nuclei (SCN) of the hypothalamus. Superimposed on this rhythmic regulation is an overriding, suppressing control by light. The pineal, in turn, regulates other rhythms in the organism via its release of melatonin into the general circulation. In man, melatonin has both a sleep-promoting effect and a role in synchronizing the sleepwake cycle. There are a variety of conditions in which melatonin regulation is altered and melatonin is a promising agent for use in treatment of circadian rhythm disorders.” From “Light, Melatonin and the Sleep-Wake Cycle” Gregory M. Brown, M.D., Ph.D., FRCP(C) The Clarke Institute of Psychiatry, Toronto, Ontario Submitted: August 13, 1993.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1188623/pdf/jpn00057-0027.pdf
http://www.ncbi.nlm.nih.gov/

Light therapy can reset the body clock by realigning circadian rhythms that are disturbed in jet lag disorder

Gooley JJ., Division of Sleep Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA. Treatment of circadian rhythm sleep disorders with light, Annals of the Academy of Medicine, Singapore. 2008 Aug;37(8):669-76.

“The human circadian system is normally synchronised with the solar day, insuring that alertness and performance peak during daytime hours and consolidated sleep occurs during the night. In circadian rhythm sleep disorders, the pattern of sleep-wake is misaligned with the patient’s circadian system or the external environment, resulting in insomnia, fatigue, and deterioration in performance. Appropriately-timed exposure to bright light can reset the timing of sleep and wake to the desired times, and improve sleep quality and daytime alertness. The efficacy of bright light therapy, however, is dependent on the time-of-day of the circadian cycle that the light is administered. In this article, we examine the physiological basis for bright light therapy, and we discuss the application of light in the treatment of circadian rhythm sleep disorders including advanced and delayed sleep-phase disorder, free-running disorder (nonentrained type), shift work disorder and jet lag disorder. We review the laboratory and field studies which have established bright light therapy as an effective treatment for sleep-wake and circadian misalignment, and we also provide guidelines for the appropriate timing and safe use of bright light therapy.”

http://www.ncbi.nlm.nih.gov/pubmed/18797560
http://www.ncbi.nlm.nih.gov/

Kolla BP, Auger RR. Jet lag and shift work sleep disorders: how to help reset the internal clock. Cleveland Clinic Journal of Medicine. 2011 Oct;78(10):675-84. doi: 10.3949/ccjm.78a.10083. Mayo Center For Sleep Medicine, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.

“Jet lag sleep disorder and shift work sleep disorder are the result of dyssynchrony between the internal clock and the external light-dark cycle, brought on by rapid travel across time zones or by working a nonstandard schedule. Symptoms can be minimized by optimizing the sleep environment, by strategic avoidance of and exposure to light, and also with drug and behavioral therapies.”

http://www.ncbi.nlm.nih.gov/pubmed/21968474
http://www.ncbi.nlm.nih.gov/

Lack LC, Wright HR. Chronobiology of sleep in humans. Cellular and Molecular Life Sciences. 2007 May;64(10):1205-15. School of Psychology, Flinders University, Adelaide, South Australia, Australia. Leon.lack@flinders.edu.au.

“Periodic circadian (24-h) cycles play an important role in daily hormonal and behavioural rhythms. Usually our sleep/wake cycle, temperature and melatonin rhythms are internally synchronized with a stable phase relationship. When there is a desynchrony between the sleep/wake cycle and circadian rhythm, sleep disorders such as advanced and delayed sleep phase syndrome can arise as well as transient chronobiologic disturbances, for example from jet lag and shift work. Appropriately timed bright light is effective in re-timing the circadian rhythm and sleep pattern to a more desired time, ameliorating these disturbances. Other less potent retiming effects may also be obtained from the judicious use of melatonin and exercise.”

http://www.ncbi.nlm.nih.gov/pubmed/17364140
http://www.ncbi.nlm.nih.gov/

Parry BL. Jet lag: minimizing it’s effects with critically timed bright light and melatonin administration. Journal of Molecular Microbiology and Biotechnology. 2002 Sep;4(5):463-6. University of California, San Diego, La Jolla 92093-0804, USA. bparry@ucsd.edu.

“The symptoms of jet lag cause distress to an increasing number of travelers. Potentially they may impair sleep, mood and cognitive performance. Critically timed exposure to bright light and melatonin administration can help to reduce symptoms. Bright light is one of the most powerful synchronizers of human rhythms and melatonin serves as a “dark pulse” helping to induce nighttime behaviors. Thus, enhancing day and night signals to the brain, appropriate to the environmental light/dark cycle of the new time zone, can serve to reestablish adaptive timing relationships between the body’s internal biological rhythms and the external environment, and thereby reduce the symptoms of jet lag. Specific recommendations using bright light and melatonin for eastward and westward travel before and after departure are provided for time zone changes of up to 6, 7-9 and 10 or more hours.”

http://www.ncbi.nlm.nih.gov/pubmed/12432956
http://www.ncbi.nlm.nih.gov/

Paul MA, Miller JC, Love RJ, Lieberman H, Blazeski S, Arendt J. Timing light treatment for eastward and westward travel preparation. Chronobiology Internation. 2009 Jul;26(5):867-90. Defence Research and Development Canada, Toronto, Canada. michel.paul@drdc-rddc.gc.ca

“Jet lag degrades performance and operational readiness of recently deployed military personnel and other travelers. The objective of the studies reported here was to determine, using a narrow bandwidth light tower (500 nm), the optimum timing of light treatment to hasten adaptive circadian phase advance and delay. Three counterbalanced treatment order, repeated measures studies were conducted to compare melatonin suppression and phase shift across multiple light treatment timings…. These data suggest largest phase advances will result when light treatment is started between 06:00 and 08:00 h, and greatest phase delays will result from light treatment started between 02:00 to 03:00 h in entrained subjects with a regular sleep wake cycle (23:00 to 07:00 h).”

http://www.ncbi.nlm.nih.gov/pubmed/19637048
http://www.ncbi.nlm.nih.gov/

Bjorvatn B, Holsten F. [Phototherapy of jet lag, night work and sleep disorders]. Tidsskr Nor Laegeforen. 1997 Jun 30;117(17):2489-92. Søvnlaboratoriet, Universitetet i Bergen.

“Jet lag, complaints associated with night work, and certain sleep disorders may be caused by misalignment between the endogenous circadian rhythm and the sleep/wake cycle. The authors discuss how light influences and regulates the circadian rhythm. The endogenous circadian rhythm is generated by the suprachiasmatic nucleus, and the effect of light is mediated to this nucleus directly via the retinohypothalamic tract. The effect is dependent on the timing of the light exposure relative to the nadir of the endogenous rhythm, which usually is located at about 5:00 AM. Exposure to bright light before nadir induces a phase delay, whereas a phase advance is obtained with exposure to light after nadir. The paper describes how bright light treatment can be used to reduce the effects of jet lag and of night work, sleep phase disturbances and early morning awakenings. Melatonin administration is an alternative treatment for the same type of disorders, and is also discussed in the article.”

http://www.ncbi.nlm.nih.gov/pubmed/9265312
http://www.ncbi.nlm.nih.gov/

Seniors

Light therapy improves sleep for seniors

Campbell SS, Dawson D, Anderson MW, Alleviation of sleep maintenance insomnia with timed exposure to bright light, Journal of the American Geriatrics Society, 1993 Aug;41(8):829-36. Department of Psychiatry, Cornell University Medical College, White Plains, New York 10605

“Half of the population over 65 suffers from chronic sleep disturbance. As a consequence, almost 40% of hypnotic medications are prescribed to people over age 60. Yet, hypnotics are often of little benefit in this population. As such, an effective non-drug alternative could prove important in the management of age-related sleep maintenance insomnia. The current study sought to evaluate the efficacy of bright light exposure in the treatment of sleep maintenance insomnia.” “The findings demonstrate the effectiveness of timed exposure to bright light in the treatment of age-related sleep maintenance insomnia. With further refinement of treatment regimens, this non-drug intervention may prove useful in a large proportion of sleep disturbed elderly.”

http://www.ncbi.nlm.nih.gov/pubmed/8340561?dopt=Abstract
http://www.ncbi.nlm.nih.gov/

Murphy PJ, Campbell SS., Enhanced performance in elderly subjects following bright light treatment of sleep maintenance insomnia, Journal of Sleep Research. 1996 Sep;5(3):165-72. Department of Psychiatry, Cornell Medical College, New York, USA. pjmurphy@med.cornell.edu

“Sixteen older individuals with sleep maintenance insomnia were treated with night-time bright-light exposure (BL) while living at home. Twelve consecutive days of acute light treatment were followed by a 3-mo maintenance light-treatment period. Subjects completed laboratory evaluation sessions on five separate occasions (prior to and following the acute light-treatment period, and once per month during the maintenance period). During each laboratory session, performance levels, sleep, and core body temperature were measured. The performance battery consisted of four computerized tasks (Logical Reasoning, Stroop Congruency, Two Letter Visual Search, and Wilkinson Four-Choice Reaction Time) and was administered every 2 h between 10.00 and 18.00 hours. Subjects improved significantly on three of the four tasks from pre-BL to post-BL. During the maintenance period, subjects who received active BL treatment maintained significantly higher performance levels than a control BL group. Light treatment improved sleep efficiency and delayed the phase of the body temperature rhythm. Performance improvements were significantly related only to sleep and not to circadian phase. The implications for non-circadian treatments of sleep maintenance insomnia and cognitive functioning in the elderly are discussed.”

http://www.ncbi.nlm.nih.gov/pubmed/8956206?dopt=Abstract
http://www.ncbi.nlm.nih.gov/

Sleep problems for seniors are due to circadian rhythm disturbances

Ancoli-Israel S, Sleep problems in older adults: putting myths to bed, Geriatrics. 1997 Jan;52(1):20-30. Department of Psychiatry, University of California, San Diego, USA.

“Many people believe that older adults need less sleep. However, it is not the need for sleep but the ability to sleep that diminishes with age. Older adults are objectively sleepier in the day, indicating they are not getting enough sleep at night. Their sleep is disrupted by circadian rhythm changes, disorders such as sleep disordered breathing (apnea) and periodic limb movements in sleep (PLMS), medical illness, psychiatric illness, medication use, and poor sleep habits. The physician can address each of these causes, thereby improving the night-time sleep and daytime functioning of the older adult.”

http://www.ncbi.nlm.nih.gov/pubmed/9003201?dopt=Abstract
http://www.ncbi.nlm.nih.gov/

R. J. Davenport, Up All Night, Science’s SAGE KE (31 July 2002).

“As we age, the internal clock that coordinates our physiology with the 24-hour day falters. New research provides the first glimpse at molecular changes that underlie the mistiming. The results suggest that aging disrupts the connection between the brain’s central clock and timekeepers elsewhere in the body.”

“Sleep problems, which commonly trouble the elderly, aren’t just an annoyance. Lack of sleep can impair memory, disrupt metabolism, and perhaps even hasten death. In addition, disjointed internal clocks prompt many Alzheimer’s patients to do things at inappropriate times.”

“Tracking other components of circadian clocks and deciphering how they break down in elderly animals could awaken researchers to the cause of old-age sleeplessness.”

http://sageke.sciencemag.org/cgi/content/abstract/sageke;2002/30/nw104
http://sageke.sciencemag.org

Van Someren EJ., Circadian rhythms and sleep in human aging. Chronobiology International. 2000 May;17(3):233-43. Netherlands Institute for Brain Research, Amsterdam. e.van.someren@nih.knaw.nl.

“This issue of Chronobiology International is dedicated to the age-related changes in circadian rhythms as they occur in humans. It seems timely to give an overview of the knowledge and hypotheses on these changes now that we enter a century in which the number and percentage of elderly in the population will be unprecedented. Although we should take care not to follow the current tendency to think of old age as a disease–ignoring the fine aspects of being old–there is definitely an age-related increase in the risk of a number of conditions that are at least uncomfortable. Circadian rhythms have been attributed adaptive values that usually go unnoticed, but can surface painfully clear when derangements occur. Alterations in the regulation of circadian rhythms are thought to contribute to the symptoms of a number of conditions for which the risk is increased in old age (e.g., sleep disturbances, dementia, and depression). A multidisciplinary approach to investigate the mechanisms of age-related changes in circadian regulation eventually may result in treatment strategies that will improve the quality of life of the growing number of elderly. Although diverse topics are addressed in this issue, the possible mechanisms by which a deranged circadian timing system may be involved in sleep disturbances receives the most attention. This seems appropriate in view of the numerous studies that have addressed this relation in the last decade and also because of the high frequency and strong impact of sleep disturbances in the elderly. This introduction to the special issue first briefly addresses the impact of disturbed sleep in the elderly to show that the development of therapeutic methods other than the currently available pharmacological treatments should be given high priority. I believe that chronobiological insights may play an important role in the development of rational therapeutical methods.”

http://www.ncbi.nlm.nih.gov/pubmed/10841205
http://www.ncbi.nlm.nih.gov/

Van Cauter E, Plat L, Leproult R, Copinschi G., Alterations of circadian rhythmicity and sleep in aging: endocrine consequences. Hormone Research. 1998;49(3-4):147-52. Department of Medicine, University of Chicago, Ill 60637, USA. evcauter@medicine.bsd.uchicago.edu

“All 24-hour endocrine rhythms partially reflect the interaction of circadian rhythmicity with sleep-wake homeostasis but their relative contributions vary from one system to another. In older adults, many 24-hour rhythms are dampened and/or advanced, including those of cortisol and GH. Amplitude reduction and phase advance of 24-hour rhythms may represent age-related changes in the central nervous systems underlying circadian rhythmicity and sleep-wake homeostasis. Age-related alterations in circadian function could also reflect decreased exposure and/or responsivity to the synchronizing effects of both photic (e.g. light exposure) and nonphotic (e.g. social cues) inputs. There are pronounced age-related alterations in sleep quality in aging which consist primarily of a marked reduction of slow-wave sleep, a reduction in REM stages and a marked increase in the number and duration of awakenings interrupting sleep. Alterations in slow-wave sleep occur abruptly in young adulthood (30-40 years of age) whereas disturbances in amounts of REM and wake appear more gradually. This article reviews evidence indicating that deficits in characteristics of sleep-wake homeostasis and circadian function may mediate age-related alterations in somatotropic and corticotropic function. Because sleep loss in young subjects results in endocrine disturbances which mimic those observed in aging, it is conceivable that the decrease in sleep quality which characterizes aging may contribute to age-related alterations in hormonal function and their metabolic consequences.”

http://www.ncbi.nlm.nih.gov/pubmed/9550116
http://www.ncbi.nlm.nih.gov/

Light therapy improves sleep and circadian rhythm disturbances in seniors with dementia and Alzheimer’s disease

Yamadera H, Ito T, Suzuki H, Asayama K, Ito R, Endo S., Effects of bright light on cognitive and sleep-wake (circadian) rhythm disturbances in Alzheimer-type dementia. Psychiatry and Clinical Neurosciences. 2000 Jun;54(3):352-3. Department of Neuropsychiatry, Nippon Medical School, Tamanagayama Hospital, Tama, Tokyo, Japan. yamadera@nms.ac.jp.

“Twenty-seven patients with Alzheimer-type dementia (ATD) were treated with bright light therapy in the morning for four consecutive weeks. The cognitive state of each patient was evaluated with the Mini-Mental-State Examination (MMSE) and circadian rhythm with actigram before and after therapy for all of the patients and those of two groups divided by the severity criteria of the Clinical Dementia Rating. The therapy improved the circadian rhythm disturbances. Although the therapy caused no remarkable effects on dementia severity, it improved the MMSE scores, especially in the early stages of ATD. These results suggest that bright light therapy improved the circadian rhythm disturbances and then bettered the cognitive state in early-stage ATD.”

http://www.ncbi.nlm.nih.gov/pubmed/11186110?dopt=Abstract
http://www.ncbi.nlm.nih.gov/

Satlin A, Volicer L, Ross V, Herz L, Campbell S., Bright light treatment of behavioral and sleep disturbances in patients with Alzheimer’s disease. The American Journal of Psychiatry. 1992 Aug;149(8):1028-32. Department of Psychiatry, Harvard Medical School, Belmont, Mass.

“OBJECTIVE: The authors tested the hypothesis that evening bright light pulses would improve sleep-wake patterns and reduce agitation in patients with Alzheimer’s disease who have severe sundowning (a syndrome of recurring confusion and increased agitation in the late afternoon or early evening) and sleep disorders. METHOD: Ten inpatients with Alzheimer’s disease on a research ward of a veterans’ hospital were studied in an open clinical trial. All patients had sundowning behavior and sleep disturbances. After a week of baseline measurements, patients received 2 hours/day of exposure to bright light between 7:00 p.m. and 9:00 p.m. for 1 week. During the baseline week, the treatment week, and a posttreatment week, patients were rated by nurses for agitation, sleep-wake patterns, use of restraints, and use of prescribed-as-needed medication. On the last 2 days of each week, patients wore activity monitors. Activity counts were analyzed for circadian rhythmicity. RESULTS: Clinical ratings of sleep-wakefulness on the evening nursing shift improved with light treatment in eight of the 10 patients. The proportion of total daily activity occurring during the nighttime decreased during the light-treatment week. The relative amplitude of the circadian locomotor activity rhythm, a measure of its stability, increased during the light-treatment week. More severe sundowning at baseline predicted greater clinical improvement. CONCLUSIONS: Evening bright light pulses may ameliorate sleep-wake cycle disturbances in some patients with Alzheimer’s disease. This effect may be mediated through a chronobiological mechanism..”

http://www.ncbi.nlm.nih.gov/pubmed/1353313
http://www.ncbi.nlm.nih.gov/

Koyama E, Matsubara H, Nakano T., Bright light treatment for sleep-wake disturbances in aged individuals with dementia. Psychiatry and Clinical Neurosciences.1999 Apr;53(2):227-9. Department of Neuropsychiatry, Home Appliance R&D Laboratory, Matsushita Electric Works, Ltd., Osaka, Japan.

“Treatment using bright light exposure was carried out on six aged subjects with dementia in two nursing homes. Sleep logs were recorded by the staff. Bright light treatment was applied in the late morning every day. The %sleep in the lights-out period and/or the %wake in daytime increased in three subjects. In the other three subjects, sleep onset time was advanced. In all subjects abnormal behavior episodes around the lights-out time tended to be reduced. These results suggest that bright light treatment is effective in improving the sleep-wake disturbances of aged individuals with dementia.”

http://www.ncbi.nlm.nih.gov/pubmed/10459695
http://www.ncbi.nlm.nih.gov/

Light therapy decreases depression in seniors

Sumaya IC, Rienzi BM, Deegan JF 2nd, Moss DE., Bright light treatment decreases depression in institutionalized older adults: a placebo-controlled crossover study. The Journals of Gerontology. Series A, Biological Sciences and Medical Sciences. 2001 Jun;56(6):M356-60. Laboratory of Psychobiochemistry, University of Texas at El Paso, USA. icsumaya@utep.edu.

“An important parallel exists between patients with seasonal affective disorder and institutionalized older adults. Many older patients, as a result of global physical decline and immobility, are confined to their rooms, experiencing little natural sunlight. Thus, institutionalized older adults are at risk for chronic light deprivation. Testing the hypothesis that chronic light deprivation might be responsible, at least in part, for some depression among institutionalized older adults, the aim of this study was to investigate the efficacy of morning bright light treatment on depression among older adults residing in a long-term care facility.”

“The results of the present study suggest that bright light treatment may be effective among institutionalized older adults, providing nonpharmacological intervention in the treatment of depression. Furthermore, the length of institutionalization may play an important role in determining the efficacy of bright light treatment for older adults in the nursing-home setting.”

http://www.ncbi.nlm.nih.gov/pubmed/11382795
http://www.ncbi.nlm.nih.gov/

Lieverse R, Van Someren EJ, Nielen MM, Uitdehaag BM, Smit JH, Hoogendijk WJ., Bright Light Treatment in Elderly Patients With Nonseasonal Major Depressive Disorder. Archives of General Psychiatry. 2011 Jan;68(1):61-70.. Department of Psychiatry, VU University Medical Center, Amsterdam, the Netherlands. ritsaert.lieverse@gmail.com

“CONTEXT: Major depressive disorder (MDD) in elderly individuals is prevalent and debilitating. It is accompanied by circadian rhythm disturbances associated with impaired functioning of the suprachiasmatic nucleus, the biological clock of the brain. Circadian rhythm disturbances are common in the elderly. Suprachiasmatic nucleus stimulation using bright light treatment (BLT) may, therefore, improve mood, sleep, and hormonal rhythms in elderly patients with MDD.”

“CONCLUSIONS: In elderly patients with MDD, BLT improved mood, enhanced sleep efficiency, and increased the upslope melatonin level gradient. In addition, BLT produced continuing improvement in mood and an attenuation of cortisol hyperexcretion after discontinuation of treatment.”

http://www.ncbi.nlm.nih.gov/pubmed/21199966
http://www.ncbi.nlm.nih.gov/

The eye’s role in detecting light to maintain health

Laurie Tarkan. Your eyes may be the windows to a faster aging process. The New York Times, Herald-Tribune (Tuesday, February 21, 2012)

The New York Times reported on February 221, 2012 that people whose circadian rhythms are out of sync, like shift workers, are at greater risk for a number of ailments, including insomnia, heart disease and cancer, and that researchers have discovered that the body clock relies on light to function properly. According to Dr. David Berson, of Brown University in Providence, R.I, the role of synchronizing our circadian rhythms lies with the eye, which detects light through specialized cells and then sends signals to the brain to release the hormones that our body needs to function properly throughout the day.

http://health.heraldtribune.com/2012/02/21/your-eyes-may-be-the-windows-to-a-faster-aging-process/

Low levels of melatonin linked to poor immune system function

Cardinali DP, Esquifino AI, Srinivasan V, Pandi-Perumal SR., Melatonin and the immune system in aging. Neuroimmunomodulation. 2008;15(4-6):272-8. Epub 2008 Nov 26. Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina. dcardinali@fmed.uba.ar

“Aging is associated with a decline in immune function (immunosenescence), a condition known to correlate with increased incidence of cancer as well as infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration with age. Circulating melatonin decreases with age, and in recent years much interest has been focused on its immunomodulatory effect. Melatonin stimulates the production of progenitor cells for granulocytes and macrophages. It also stimulates the production of natural killer cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from natural killer cells and T helper lymphocytes are enhanced by melatonin. Melatonin has the potential therapeutic value to enhance immune function in aged individuals.”

http://www.ncbi.nlm.nih.gov/pubmed/19047804
http://www.ncbi.nlm.nih.gov/