Light therapy

International Journal of Dermatology

The effectiveness of light therapy for treating SAD may be linked to the fact that light therapy makes up for lostsunlightexposure and resets the bodys internal clock.19Studies show that light therapy helps reduce the debilitating and depressive behaviors of SAD, such as excessive sleepiness and fatigue, with results lasting for at least 1 month. Light therapy is preferred over antidepressants in the treatment of SAD because it is a relatively safe and easy therapy.20

European Commission; Directorate-General for Employment, Social Affairs and Inclusion (2011),

From Wikipedia, the free encyclopedia

Text is available under the; additional terms may apply. By using this site, you agree to theTerms of UseandPrivacy Policy. Wikipedia® is a registered trademark of theWikimedia Foundation, Inc., a non-profit organization.

Barkham.One face, but two sides of a story.

In treatment, the patients eyes are to be at a prescribed distance from the light source with the light striking the (lower) retina. This does not require looking directly into the light.

Bjorvatn, Bjørn; Pallesen, Ståle (February 2009). A practical approach to circadian rhythm sleep disorders.

Light boxes should have been tested successfully in peer-reviewedclinical trials.

Mårtensson B, Pettersson A, Berglund L, Ekselius L (2015). Bright white light therapy in depression: A critical review of the evidence.

Willis G. L.; Moore C.; Armstrong S. M. (2012). A historical justification for and retrospective analysis of the systematic application of light therapy in Parkinsons disease.

. Nobel Media AB. 2016-11-01.Archivedfrom the original on 2016-10-22

Not to be confused withLow level laser therapy.

: 11824. 2014-11-12.doi10.1111/j.1600-0781.2005.00159.xPMID15888127.

Smith MR, Eastman CI (December 2008).Night shift performance is improved by a compromise circadian phase position: study 3. Circadian phase after 7 night shifts with an intervening weekend off.

Bouzari N, Elsaie ML, Nouri K (2012). Laser and Light for Wound Healing Stimulation. In Nouri K.

Light therapyorphototherapy, classically referred to asheliotherapyconsists of exposure todaylightor to specificwavelengthsoflightusinglaserslight-emitting diodesfluorescent lampsdichroiclamps or very bright,full-spectrum light. The light is administered for a prescribed amount of time and, in some cases, at a specific time of day.

(2): e7.doi10.1371/journal.pctr.0020007PMC

Prasko J (November 2008). Bright light therapy.

Light therapy uses either a light box which emits up to 10,000luxof light at a specified distance, much brighter than a customary lamp, or a lower intensity of specific wavelengths of light from the blue (460nm) to the green (525nm) areas of thevisible spectrum.37A 1995 study showed that green light therapy at doses of 350 lux produces melatonin suppression and phase shifts equivalent to 10,000 lux white light therapy,3839but another study published in May 2010 suggests that the blue light often used for SAD treatment should perhaps be replaced by green or white illumination, because of a possible involvement of theconesin melatonin suppression.40

(2): 17186.doi10.1097/00000-00006PMID15257218.

Diffey BL (1980). Ultraviolet radiation physics and the skin.

All articles with specifically marked weasel-worded phrases

Main article:Circadian rhythm sleep disorder

: 17.doi10.1016/j.jad.2015.04.013PMID25942575.

Many ancient cultures practiced various forms of heliotherapy, including people ofAncient GreeceAncient Egypt, andAncient Rome.59TheIncaAssyrianand earlyGermansettlers also worshipped the sun as a health bringingdeity. Indian medical literature dating to 1500 BCE describes a treatment combiningherbswith natural sunlight to treat non-pigmented skin areas.Buddhist literaturefrom about 200 CE and 10th-century Chinese documents make similar references.

Newman TB, Kuzniewicz MW, Liljestrand P, Wi S, McCulloch C, Escobar GJ (May 2009).Numbers needed to treat with phototherapy according to American Academy of Pediatrics guidelines.

Journal of the American Academy of Physician Assistants

. 29 Suppl 1: 3364.PMID19029878.

Light therapy has been trialed in treating sleep disorders experienced by patients with Parkinsons disease.34

Epstein, Franklin H.; Gilchrest, Barbara A.; Eller, Mark S.; Geller, Alan C.; Yaar, Mina (29 April 1999). The Pathogenesis of Melanoma Induced by Ultraviolet Radiation.

Sanassi Lorraine A (2014). Seasonal affective disorder: Is there light at the end of the tunnel?.

The Nobel Prize in Physiology or Medicine 1903.

Side effects of light therapy for sleep phase disorders include jumpiness or jitteriness,headache, eye irritation andnausea.57Some non-depressive physical complaints, such as poor vision and skin rash or irritation, may improve with light therapy.58

Circadian rhythm sleep disorders and jet lag

Articles with unsourced statements from August 2012

Evidence for light therapy andlasersinacne vulgarisas of 2012 is not sufficient to recommend them.7There is moderate evidence for the efficacy of blue and blue-red light therapies in treating mild acne, but most studies are of low quality.89While light therapy appears to provide short term benefit, there is a lack of long term outcome data or data in those with severe acne.10

Tuunainen, A; Kripke, DF; Endo, T (2004). Tuunainen, Arja, ed. Light therapy for non-seasonal depression.

Pei S, Inamadar AC, Adya KA, Tsoukas MM (2015).Light-based therapies in acne treatment.

(2): 6981.doi10.1016/j.tmaid.2008.09.004PMID19237140.

Zisapel, Nava (2001). Circadian Rhythm Sleep Disorders.

Hamilton FL, Car J, Lyons C, Car M, Layton A, Majeed A (June 2009). Laser and other light therapies for the treatment of acne vulgaris: systematic review.

Depression (differential diagnoses)

Further information:Neonatal jaundice

(3): 14557.doi10.4103/2229-5178.156379PMC

Titus S, Hodge J (October 2012).Diagnosis and treatment of acne.

(2): 1822.doi10.1097/01.jaa.0000442698.03223.f3.

Clinical, Cosmetic and Investigational Dermatology

Light Therapy Topic Overview. WebMD. 30 June 2009

: 35560.doi10.1111/j.1365-4632.2004.02186.xPMID15869531.

(2): 383400.doi10.1007/s1-xPMID23722672.

(3): 298308.doi10.1016/j.taap.2003.08.019PMID15020192.

(8): 555561.doi10.1111/j.1365-4632.2004.02032.xPMID15304175.

Neonatal jaundice (Postnatal Jaundice)

Bright Light May Boost TestosteroneWebMD

(2): 14044.doi10.1046/j.1600-079X.2003.00108.xPMID14962066.

Terman M, Terman JS (August 2005). Light therapy for seasonal and nonseasonal depression: efficacy, protocol, safety, and side effects.

Sleep disorder in Parkinsons disease

Arden, G. B.; Sivaprasad, S. (2012-02-03).The pathogenesis of early retinal changes of diabetic retinopathy.

Edwards, Martin.Dora Colebrook and the evaluation of light therapy.

Wright HR, Lack LC, Kennaway DJ (March 2004). Differential effects of light wavelength in phase advancing the melatonin rhythm.

Cochrane Database of Systematic Reviews

Thompson C, Stinson D, Smith A (September 1990). Seasonal affective disorder and season-dependent abnormalities of melatonin suppression by light.

In the management ofcircadian rhythmdisorders such asdelayed sleep phase disorder(DSPD), the timing of light exposure is critical. Light exposure administered to the eyes before or after thenadirof the core body temperature rhythm can affect thephase response curve.30Use upon awakening may also be effective fornon-24-hour sleepwake disorder.31Some users have reported success with lights that turn on shortlybeforeawakening (dawn simulation). Evening use is recommended for people withadvanced sleep phase disorder. Some, but not all, totally blind people whose retinae are intact, may benefit from light therapy.

What is Psoriasis: What Causes Psoriasis?. 29 January 2012

Low level laser therapyhas been studied as a potential treatment forchronic wounds.15Reviews of the scientific literature do not support the widespread use of this technique due to inconsistent results and low research quality.1516Higher power lasers have also been used to close acute wounds as an alternative tostitching.15

According to theAmerican Cancer Society, there is some evidence that ultraviolet light therapy may be effective in helping treat certain kinds ofskin cancer, and ultravioletblood irradiation therapyis established for this application. However, alternative uses of light for cancer treatment light box therapy andcolored light therapy are not supported by evidence.11Photodynamic therapy (often with red light) is used to treat certain superficial non-melanoma skin cancers.12

Patrizi, A; Raone, B; Ravaioli, GM (5 October 2015).Management of atopic dermatitis: safety and efficacy of phototherapy.

Light therapy has also been suggested in the treatment of non-seasonal depression and other psychiatric mood disturbances, includingmajor depressive disorder,24bipolar disorderandpostpartum depression.2526A meta-analysis by theCochrane Collaborationconcluded that for patients suffering from non-seasonal depression, light therapy offers modest though promising antidepressive efficacy.27A 2008systematic reviewconcluded that overall, bright light therapy is an excellent candidate for inclusion into the therapeutic inventory available for the treatment of nonseasonal depression today, as adjuvant therapy to antidepressant medication, or eventually as stand-alone treatment for specific subgroups of depressed patients.28A 2015 review found that supporting evidence for light therapy was limited due to seriousmethodologicalflaws.29

Roger DR (2007-12-04).Practical aspects of light therapy. American Medical Network

Neonatal jaundice (Postnatal Jaundice)

A 2007systematic reviewby the Swedish agency SBU found insufficient evidence that light therapy was able to alleviate symptoms of depression or seasonal affective disorder.22The report recommended that: Approximately 100 participants are required to establish whether the therapy is moderately more effective than placebo.22Although treatment in light therapy rooms was well established in Sweden, no satisfactory, controlled studies had been published on the subject.22This led to the closure of a number of clinics offering light therapy in Sweden.23

Articles with specifically marked weasel-worded phrases from April 2014

(2): 18992.doi10.1038/eye.2015.254PMC

Engines of our Ingenuity No. 1769: NIELS FINSEN

(8717): 70306.doi10.1016/0140-6736(90)92202-SPMID1975891.

Morton, C.A.; Brown, S.B.; Collins, S.; Ibbotson, S.; Jenkinson, H.; Kurwa, H.; Langmack, K.; Mckenna, K.; Moseley, H.; Pearse, A.D.; Stringer, M.; Taylor, D.K.; Wong, G.; Rhodes, L.E. (April 2002). Guidelines for topical photodynamic therapy: report of a workshop of the British Photodermatology Group.

The brightness andcolor temperatureof light from a light box are quite similar to daylight.

Glazer-Hockstein C, Dunaief JL (January 2006). Could blue light-blocking lenses decrease the risk of age-related macular degeneration?.

Photodynamic therapy is a form of phototherapy using nontoxic light-sensitive compounds that are exposed selectively to light, whereupon they become toxic to targeted malignant and other diseased cells

Terman M (December 2007). Evolving applications of light therapy.

Danilenko KV, Samoilova EA (2007).Stimulatory effect of morning bright light on reproductive hormones and ovulation: results of a controlled crossover trial.

Forpsoriasis, UVB phototherapy has been shown to be effective.4A feature of psoriasis is localizedinflammationmediated by theimmune system.5Ultravioletradiation is known to suppress theimmune systemand reduce inflammatory responses. Light therapy for skin conditions like psoriasis usually use NB-UVB (311nm wavelength) though it may useUV-A(315400nm wavelength) orUV-B(280315nm wavelength) light waves. UV-A, combined withpsoralen, a drug taken orally, is known asPUVAtreatment. In UVB phototherapy the exposure time is very short, seconds to minutes depending on intensity of lamps and the persons skin pigment and sensitivity. The time is controlled with a timer that turns off the lamps after the treatment time ends.

Smaller is not better; when using a compact light box, even small head movements will take the eyes out of the therapeutic range of the light.

Contraindicationsto light therapy for seasonal affective disorder include conditions that might render the eyes more vulnerable tophototoxicity, tendency toward mania, photosensitive skin conditions, or use of a photosensitizing herb (such asSt. Johns wort) or medication.5556Patients withporphyriashould avoid most forms of light therapy. Patients on certain drugs such asmethotrexateorchloroquineshould use caution with light therapy as there is a chance that these drugs could cause porphyria.citation needed

(3): 33440.doi10.1111/j.1524-4725.2005.31086PMID15841638.

(1): 1526.doi10.1007/s1-yISSN0012-4486.

Articles with unsourced statements from October 2014

Yam, Jason C. S.; Kwok, Alvin K. H. (31 May 2013). Ultraviolet light and ocular diseases.

How Finsens light cured lupus vulgaris.

Articles with unsourced statements from April 2014

CS1 maint: Uses authors parameter (link)

Light therapy which strikes theretinaof the eyes is used to treatdiabetic retinopathyand alsocircadian rhythmdisorders such asdelayed sleep phase disorderand can also be used to treatseasonal affective disorder, with some support for its use also with non-seasonalpsychiatric disorders.medical citation needed

Light therapy is considered one of the best monotherapy treatments for atopic dermatitis (AD), when applied to patients who have not responded to traditional topical treatments. The therapy offers a wide range of options: UVA1 for acute AD, NB-UVB for chronic AD, and balneophototherapy have proven their efficacy over the recent past. Patients tolerate the therapy safely but, as in any therapy, there are adverse effects and care should be taken in its application, particularly to children.3

Hession MT, Markova A, Graber EM (2015). A review of hand-held, home-use cosmetic laser and light devices.

Light therapy is used to treat cases ofneonatal jaundice35through theisomerizationof thebilirubinand consequently transformation into compounds that the newborn can excrete via urine and stools. A common treatment of neonatal jaundice is thebili lightorbilliblanket.

(31): 3133.doi10.1126/scitranslmed.3000741PMC

Articles with unsourced statements from January 2013

Chronic circadian rhythm sleep disorders (CRSD)

Light Therapy. American Cancer Society. 14 April 2011. Archived fromthe originalon 2015-02-12

(4): 311328.doi10.2165/00020-00005.

(4): 239246.doi10.1080/76PMID18058281.

Light box redirects here. For other uses, seeLightbox (disambiguation).

There is preliminary evidence that light therapy is an effective treatment fordiabetic retinopathyanddiabetic macular oedema.1718

Photodermatol Photoimmunol Photomed

Benedetti F, Colombo C, Pontiggia A, Bernasconi A, Florita M, Smeraldi E, (2003)

(1): 14.doi10.1097/00000-00001PMID16395131.

Center for Environmental Therapeutics

It is possible that response to light therapy for SAD could be season dependent.21Morning therapy has provided the best results because light in the early morning aids in regulating the circadian rhythm.20


Treating psoriasis: light therapy and phototherapy National Psoriasis Foundation. 2014-02-14

(6): 497507.doi10.1016/j.smrv.2007.06.003PMID17964200.

Considering three major factors clinical efficacy, ocular and dermatologic safety, and visual comfort, the Center for Environmental Therapeutics (CET) recommends the following criteria for light box selection:41

All articles with unsourced statements

Matsumura, Yasuhiro; Ananthaswamy, Honnavara N (March 2004). Toxic effects of ultraviolet radiation on the skin.

Toxicology and Applied Pharmacology

(1): 4760.doi10.1016/j.smrv.2008.04.009.

Westrin, Åsa; Lam, Raymond W. (October 2007). Seasonal Affective Disorder: A Clinical Update.

Crouch, David (2015-01-24).Swedish school sheds light on dark days of winter.

(3): 30720.doi10.1097/DSS.3PMID25705949.

Articles with unsourced statements from August 2009

Gagarina, AK (2007-12-08).Light Therapy Diagnostic Indications and Contraindications. American Medical Network

Circadian rhythm sleep disorders and jet lag

Ultravioletlight causes progressive damage to human skin anderythemaeven from small doses.4445This is mediated bygenetic damagecollagendamage, as well as destruction ofvitamin Aandvitamin Cin the skin andfree radicalgeneration.citation neededUltraviolet light is also known to be a factor in formation ofcataracts.4647Ultraviolet radiation exposure is strongly linked to incidence ofskin cancer.484449

The treatments involve exposing the skin toultraviolet light. The exposures can be to small area of theskinor over the whole body surface, like in atanning bed. The most common treatment is withnarrowbandUVB (NB-UVB) with a wavelength of 311313 nanometer. It was found that this is the safest treatment.1Full body phototherapy can be delivered at a doctors office or at home using a large high power UVB booth.2

Extracorporeal assistance, performance, and therapy (ICD-9-CM V399,ICD-10-PCS 5-6)

(2): 199226.doi10.1515/revneuro-2011-0072PMID22499678.

Daoudi, R (April 2018). Can the light be used to treat obesity and diabetes?.arXiv:

Light box redirects here. For other uses, seeLightbox (disambiguation).

. Springer London. pp.26775.doi10.1007/978-0-85729-281-0_20ISBN978-0-85729-281-0.

The magnitude of the phase shifts [using low-level green light therapy] are comparable to those obtained using high-intensity white light in winter-depressives.

One percent of the population suffer fromvitiligo, and narrowband UVB phototherapy is an effective treatment. NB-UVB phototherapy results in satisfactory repigmentation in our vitiligo patients and should be offered as a treatment option.6

Fluorescent lampsshould have a smooth diffusing screen that filters out ultraviolet (UV) rays. UV rays are harmful to the eyes and skin.

. Royal College of Physicians of Edinburgh and Minervation Ltd

Since then a large array of treatments using controlled light have been developed. Though the popular consumer understanding of light therapy is associated with treatingseasonal affective disordercircadian rhythm disordersand skin conditions likepsoriasis, other applications include the use oflow level laserredlight, near-infraredandultravioletlights forpain managementhair growth,citation neededskin treatments,which?and acceleratedwound healing.citation needed

Saeeduddin Ahmed; Neil L Cutter; Alfred J. Lewy; Vance K. Bauer; Robert L Sack; Mary S. Cardoza (1995). Phase Response Curve of Low-Intensity Green Light in Winter Depressives.

(8): 64763; quiz 672.PMID16041296.

(6): 127385.doi10.1111/j.1365-2133.2009.09047.xPMID19239470.

The light should be projected downward toward the eyes at an angle to minimize aversivevisual glare.

Theis believed to be the father of modern phototherapy. He developed the first artificial light source for this purpose.citation neededFinsen used short wavelength light to treatlupus vulgaris, a skin infection caused byMycobacterium tuberculosis. He thought that the beneficial effect was due to ultraviolet light killing thebacteria, but recent studies showed that his lens and filter system did not allow such short wavelengths to pass through, leading instead to the conclusion that light of approximately 400 nanometers generatedreactive oxygenthat would kill the bacteria.60Finsen also used red light to treatsmallpoxlesions. He received theNobel Prize in Physiology or Medicinein 1903.61Scientific evidence for some of his treatments is lacking, and later eradication of smallpox and development ofantibioticsfortuberculosisrendered light therapy obsolete for these diseases.62

(2): CD004050.doi10.1002/14651858.CD004050.pub2PMID15106233.

Lee E, Koo J, Berger T (2014-01-24). UVB phototherapy and skin cancer risk: a review of the literature.

A newborn infant undergoing white-light phototherapy to treat neonatal jaundice.

Phototherapy can be effective in the treatment ofeczemaatopic dermatitispolymorphous light eruptioncutaneous T-cell lymphoma13andlichen planus. Narrowband UVB lamps, 311313 nanometer is the most common treatment.14

Even, C; Schröder, CM; Friedman, S; Rouillon, F (2008). Efficacy of light therapy in nonseasonal depression: A systematic review.

A recent study proposes a theoretical model that may be used to treat obesity and diabetes, it uses light-induced thermogenesis.43

(5): 135259.doi10.1542/peds.2008-1635PMC

(3): 40526.Bibcode1980PMB….25..405Ddoi10.1088/0031-9155/25/3/001PMID6996006.

Morning light treatment hastens the antidepressant effect of citalopram: a placebo-controlled trial

Posten W, Wrone DA, Dover JS, Arndt KA, Silapunt S, Alam M (2005). Low-level laser therapy for wound healing: mechanism and efficacy.

Modern phototherapy lamps used in the treatment of seasonal affective disorder andsleep disorderseither filter out or do not emit ultraviolet light and are considered safe and effective for the intended purpose, as long asphotosensitizingdrugs are not being taken at the same time and in the absence of any existing eye conditions. Light therapy is a mood altering treatment, and just as with drug treatments, there is a possibility of triggering amanic statefrom adepressive state, causinganxietyand otherside effects. While these side effects are usually controllable, it is recommended that patients undertake light therapy under the supervision of an experienced clinician, rather than attempting to self-medicate.54

(12): 2139.doi10.1016/S0300-483X(03)00150-1.

Brown GM, Pandi-Perumal SR, Trakht I, Cardinali DP (March 2009). Melatonin and its relevance to jet lag.

Our Friend, the Sun: Images of Light Therapeutics from the Osler Library Collection, c. 19011944. Digital exhibition by theOsler Library of the History of MedicineMcGill University

(6): 50207.doi10.1016/j.biopsych.2005.07.006PMID16165105.

Glickman, G; Byrne, B; Pineda, C; Hauck, WW; Brainard, GC (Mar 15, 2006). Light therapy for seasonal affective disorder with blue narrow-band light-emitting diodes (LEDs).

The production of the hormonemelatonin, a sleep regulator, is inhibited by light and permitted by darkness as registered byphotosensitive ganglion cellsin theretina. To some degree, the reverse is true forserotonincitation needed, which has been linked to mood disorders. Hence, for the purpose of manipulatingmelatoninlevels or timing,light boxesproviding very specific types of artificialilluminationto the retina of the eye are effective.citation needed

: 51120.doi10.2147/CCID.S87987PMC

(4): 552567.doi10.1046/j.1365-2133.2002.04719.x.

Bandow, Grace D.; Koo, John Y. M. (August 2004). Narrow-band ultraviolet B radiation: a review of the current literature.

The box should provide 10,000 lux of illumination at a comfortable sitting distance. Product specifications are often missing or unverified; illuminance can be controlled using alight meter.

Optical radiationof any kind with enough intensity can cause damage to the eyes and skin including photoconjunctivitis andphotokeratitis.50Researchers have questioned whether limiting blue light exposure could reduce the risk ofage-related macular degeneration.51It is reported that bright light therapy may activate the production of reproductivehormones, such astestosteroneluteinizing hormonefollicle-stimulating hormone, andestradiol.5253

Sivaprasad S, Arden G (2016).Spare the rods and spoil the retina: revisited.

One of the treatments is using blue light withaminolevulinic acidfor the treatment ofactinic keratosis. This is not a U.S. FDA-approved treatment for acne vulgaris.36

Chronic circadian rhythm sleep disorders (CRSD)

Mayo Clinic Staff (20 March 2013).Light Therapy. Tests and Procedures. Risks. Mayo Clinic

Non-binding guide to good practice for implementing Directive 2006/25/EC artificial optical radiation

Michel A. Paul; James C. Miller; Gary Gray; Fred Buick; Sofi Blazeski; Josephine Arendt (July 2007).Circadian Phase Delay Induced by Phototherapeutic Devices.

.Swedish Agency for Health Technology Assessment and Assessment of Social Services(SBU)

(12): 1123.doi10.1016/j.jad.2007.09.008PMID17950467.

Light therapy has been tested for individuals withshift work sleep disorder,32and forjet lag.33

Media related toPhototherapyat Wikimedia Commons

Articles with unsourced statements from September 2013

Baron ED, Stevens SR (2003). Phototherapy for cutaneous T-cell lymphoma.

Ichihashi, M.; Ueda, M.; Budiyanto, A.; Bito, T.; Oka, M.; Fukunaga, M.; Tsuru, K.; Horikawa, T. (July 2003). UV-induced skin damage.

From the late nineteenth century until the early 1930s, light therapy was considered an effective and mainstream medical therapy in the UK for conditions such as varicose ulcer, sickly children and a wide range of other conditions. Controlled trials by the medical scientistDora Colebrooksupported by the Medical Research Council, indicated that light therapy was not effective for such a wide range of conditions.63

One common use of the term is associated with the treatment ofskin disorders, chieflypsoriasisacne vulgariseczemaandneonatal jaundice.medical citation needed

International Commission on Non-Ionizing Radiation, Protection. (August 2004). Guidelines on limits of exposure to ultraviolet radiation of wavelengths between 180 nm and 400 nm (incoherent optical radiation).

This page was last edited on 10 July 2018, at 04:10

Light Therapy for Depression, and Other Treatment of Seasonal Affective Disorder.

J.J. Gooley; S.M.W. Rajaratnam; G.C. Brainard; R.E. Kronauer; C.A. Czeisler; S.W. Lockley (May 2010).Spectral Responses of the Human Circadian System Depend on the Irradiance and Duration of Exposure to Light.

Adauwiyah J, Suraiya HH (December 2010). A retrospective study of narrowband-UVB phototherapy for treatment of vitiligo in Malaysian patients.

Articles with unsourced statements from November 2016

Blue light is known to be superior to red light in managing depressive symptoms which have a seasonal pattern.

1 thought on “Light therapy”

Leave a Comment