Bright Light
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Bright Light Treatment of Depression

Many modern Americans do not spend very much time outside and get much less sunlight than in times past. Since the 1980’s, intense indoor florescent lights have been used as a treatment for depression, especially for a type of depression called Seasonal Affective Disorder or SAD. SAD is also called winter depression. It is considered more common in northern latitudes as in Canada and Sweden, but is also reported in the U.S. A study from Germany reported that 11% of their severely depressed patients appeared to be suffering from SAD (J Affect Disord 1990 Aug;19(4):243-8). Symptoms of SAD besides depression are excessive sleep requirement, increased appetite, and weight gain, all symptoms of atypical depression.

While the studies on bright light treatment as less numerous and with smaller numbers of patients than would be ideal, over a dozen controlled studies have been done. Most studies report that patients randomly assigned to bright light treatment improve more than patients assigned to some other treatment, e.g. dim lights. Research suggests that bright light treatment helps winter depression or SAD the most, but may also be of benefit for recurring severe depression (Major Depressive Disorder)( Neuroendocrinol Lett 2002 Apr;23(2):109-13), severe depression during pregnancy (Am J Psychiatry 2002 Apr;159(4):666-9), and even bulimia (Compr Psychiatry 1999 Nov-Dec;40(6):442-8). It is important to note that other researchers have not find any benefit for the treatment of non-seasonal severe depression (Biol Psychiatry 1991 Aug 1;30(3):257-68).

Most studies of bright light treatment use very bright florescent lighting measured at 10,000 lux level of brightness for 30 minutes. Other studies have used 2,500 to 5,000 lux for longer periods of time up to two hours per day. While normal indoor light is only 100-300 lux, outdoors on a cloudy day is 2,000 lux when looking up and on a sunny day 5,000-10,000 lux or more.

Specially manufactured lights using full-spectrum florescent bulbs are available from a number of manufactures with costs running from $180-$250 (e.g. Northern Light Technologies, Montreal, 800-263-0066). Replacement bulbs are $30. These lights are designed to be used only 12 to 24 inches from the eyes, depending on the specific lamp purchased, in order to generate the desired 10,000 lux level. They have filters to block out ultraviolet rays. Another company even produces a light visor worn on the face like glasses that shines the light only an inch from the eyes.

Most researchers say the type of florescent lighting does not appear to make any difference. While full spectum light was used initially, regular florescent lighting appears to work just as well, is less expensive, and does not emit a significant level of harmful ultraviolet rays. A 26 watt compact florescent bulb available from Walmart for $5 each will generate a 10,000 lux level of lighting at a distance of 4 ½ inches. At 6 inches, the power falls to roughly 8,000 lumens, still very bright. A convenient swing arm light can be purchased from Menards for only $8.50. Thus, for a total of only $13.50, you have a fine light for bright light treatment when used at a very close distance and a very practical light for everyday use at a more normal distance.  If you want to be cheap, just buy the bulb and use any lamp.

When doing the bright light treatment, it is necessary for the light to strike the eyes, but it is not necessary to stare into the light. Some authors do recommend periodically looking directly into the light, but I doubt this is necessary. In any case, the individual can eat breakfast or do his or her reading and desk work for 30 minutes every morning with the bright light. While morning time is recommended, Swedish research has found that the time of day of the bright light treatment makes no difference (Acta Psychiatr Scand 1995 May;91(5):352-60).

Obviously, on sunny days, instead of indoor bright light treatment, a person can take a 30-45 minute brisk and refreshing walk outside, obtaining both the benefit of the bright natural light and of exercise.

There is the possibility that some of the benefit of bright light therapy comes from bright light increasing the vitamin D levels in the body.  Thus, there is the possibility that a vitamin D supplement (800 I.U.s) may also help or even do better than bright light therapy.  Unfortunately, vitamin D research has only picked up in the past few years and not researched psychiatry yet.  I personally recommend that all individuals over age 12 take 800 I.U.s of vitamin D per day.  This level can be obtained by taking one multivitamin and one extra vitamin D pill, both of which are very inexpensive. 

Bright Light Helped Non-Seasonal Depression: In a 5-week DB PC study of 102 patients with non-seasonal Major Depression and all treated with sertraline (Zoloft), those also treated with white very bright light (10.000 lx, 1 h/day) did significantly better on all measures of depression and anxiety compared to those treated with red dim light (50 lx, 30 min/day). Martiny K, Lunde M, et al. Hilleroed, Denmark. Adjunctive bright light in non-seasonal major depression: results from patient-reported symptom and well-being scales. Acta Psychiatr Scand 2005:111: 453-459.

Green Light Augmented Citalopram: 30 pt randomized study 40mg/d citalopram with or without 400 lux 30min. morning green light vs deactivated ion generator. 71% vs 44% response rate with benefits starting in first days. Francesco Benedetti, MD, from the Università Vita-Salute San Raffaele in Milan, Italy. J Clin Psychiatry. 2003;64:648-653

Bright Light Equals Imipramine: DB 3wk of 34 with Major Depr Recurrent rx 5000 lux x 2hr + imip 150 or placebo or imip alone found no diff with light and placebo non-signif better. Prague, Neuroendocrinol Lett 2002 Apr;23(2):109-13;

Bright Light Biology: Two thirds of 120 MDD patients categorized as severely depressed responded that their ambient environment appeared dimmer than usual compared to 21% of moderately and 14% of mildly depressed patients. J Affect Disord 2000 Dec;61(1-2):113-8; Both dim and bright light has been shown to suppress the nocturnal secretion of the pineal hormone melatonin. Investigated the melatonin suppression by dim light (200 lux) in patients with bipolar affective disorder, seasonal affective disorder and major depressive disorder. Results suggest that a supersensitive melatonin suppression to light in bipolar affective disorder (p < .005), and seasonal affective disorder (p < .05), whereas patients with major depressive disorder display similar suppression to controls. Australia, Neuropsychopharmacology 1999 Sep;21(3):408-13; White light better than red or blue. J Affect Disord 1990 Dec;20(4):209-16. fall-winter pattern of feeling worst comparable to that of patients with seasonal affective disorder (SAD) was 11.4% in our sample of major depressed inpatients. U Bonn. J Affect Disord 1990 Aug;19(4):243-8

Bright Light & 3 Cases Suicidal: Within the first week after beginning 1st time bright light therapy, two drug free bipolar subjects attempted suicide. The third recurrent MDD patient developed suicidal thoughts that were so acute and overwhelming that we had to discontinue bright light therapy and start with psychopharmacologic treatment in an inpatient setting. Vienna, J Clin Psychiatry 1997 Sep;58(9):389-92

Bright Light Extends Benefit of Partial Sleep Depression: U Vienna, 14 of 20 MDD inpts at least 40% decr HAM-D after PSD. 3000 lux bright light vs 50 lux extended benefit and no benefit for six non-responders. Biol Psychiatry 1996 Jan 1;39(1):16-21

Bright Light Helps SAD More: 90 MDD pts, 68 of whom SAD rx 1500 lumens x 2 hr x 10 days at 6 am or 6 pm. SAD patients benefited most. No difference in time of day or if atypical or carbohydrate craving. Karolinska Inst, Acta Psychiatr Scand 1995 May;91(5):352-60

Bright Light Not Help Non-SAD MDD: 42 non seasonal MDD rx without meds and with one week 2500 lux x 2 hr or 50 lux found no benefit from bright light. Berlin, Biol Psychiatry 1991 Aug 1;30(3):257-68; Also, 30 patients no benefit, altho may be same study. Pharmacopsychiatry 1990 May;23(3):151-4; 43% of 30 SAD subjects met the criteria for 'successful treatment', but none of the 3 subjects with non-seasonal depression showed any response. England. J Affect Disord 1990 Feb;18(2):129-35

Pregnancy: Antepartum Depression Treated with Bright Light: Open trial of bright light therapy in an A-B-A design was conducted for 3-5 weeks in 16 pregnant patients with major depression. The Hamilton Depression Rating Scale, Seasonal Affective Disorders Version, was administered to assess changes in mood. A follow-up questionnaire was used to assess outcome after delivery. After 3 weeks of treatment, depression improved 49%. Benefits were seen through 5 weeks of treatment. DA Oren, Yale, Am J Psychiatry 2002 Apr;159(4):666-9. J Clin Psychiatry. 2004 Mar;65(3):421-5

Pregnancy: Depression Helped by Bright Light: In a random-assignment study of 10 pregnant women with major depression using 7000 lux vs. 500 lux light boxes, benefits in the first 5 weeks were small and not statistically significant. However, in the longer 10-week trial, the presence of active versus placebo light produced a clear treatment effect (p =.001) with an effect size (0.43) similar to that seen in antidepressant drug trials. Randomized clinical trial of bright light therapy for antepartum depression: preliminary findings. Epperson CN, Terman M, Terman JS, Hanusa BH, Oren DA, Peindl KS, Wisner KL. Yale University. J Clin Psychiatry. 2004 Mar;65(3):421-5

Bright Light Helped SAD Depression, Bulimia Less: Open trial 4 weeks 10000 lumens with UV filter 30-60 min for comorbid SAD and bulimia had 56% decr depression but only 40% decr in binges and purges with only 9% bulimia free vs 45% depression free. U Brit Col, Vancouver, J Clin Psychiatry 2001 Mar;62(3):164-8

Bulimia Helped by Bright Light: 34 bulimics random DB 10000 lux white or 50 lux red found significant decrease bulimic symptoms with bright light although no change in depression scores. Cornell. Compr Psychiatry 1999 Nov-Dec;40(6):442-8

Buy Bright Lights From: Northern Light Technologies, Montreal, 800-263-0066, $180-260 for 10,000 lux at distances of 12"-24" with replacement bulbs costing $30. 85 watt florescent with large parabolic reflectors. To buy a light meter instead: (480) 348-0278 Light Meter, Lux Scale 840006, $98, 3oz. or $175 for 840022 from Technika. The more expensive one works with florescent as well as other lights, but the cheaper doesn’t do as well with florescent. Ed: It is far cheaper to buy a 100-150 watt-equivalent screw-in bulb from Menards or Wal-Mart and sit 6-8 inches from the light. I bought my own light meter and found that this works just fine for about $4-$6.

Institutionalized Elderly Helped: In a controlled study of 10 nursing home patients (83 yo aver.), received 10,000 lux x 30 min., 300 lux, or no treatment for 1 week each with a one week washout in between. Geriatric Depression Scores decreased 27% with bright light with 50% no longer in depressed range. Those with higher GDS scores did best. Bright light treatment decreases depression in institutionalized older adults: a placebo-controlled crossover study. Sumaya IC; Rienzi BM; Deegan JF; Moss DE. Univ, Texas El Paso, J Gerontol A Biol Sci Med Sci 2001 Jun;56(6):M356-60    

Bright Light Review: Michael Ferenzi, National Institute Medical Research Website 10/5/02: Californian forty to sixty year-olds spend less than one hour per day in daylight. The amount of light reaching the eyes in a living room at night is several hundred times less than what is experienced outdoors on a sunny summer's day. The scientific unit of intensity is called a lux, and intensity depends on both the power of the light source and the distance from it. The light intensity used during light therapy, up to ten thousand lux, is usually about ten times brighter than exposure to normal room lights but still much weaker than the light experienced on a sunny beach. The response to light is felt within the first week of treatment. The color of the light used in light therapy does not seem to matter much. In the first trials in the early 1980's, full spectrum light was used. This is light produced by special fluorescent lamps which release light more similar to that of the sun than conventional fluorescent lamps. The disadvantage of these lamps is their high cost and the relatively large amount of ultra violet radiation they emit. Since then, it has been found that for light therapy, conventional fluorescent lamps are as effective, less expensive and produce much less of the damaging ultra-violet radiation which over a long period of time might be harmful to the eyes. Daily light therapy treatment should start in September and last until late spring. Some reports show that the use of light therapy in advance of the development of winter symptoms is effective. The duration of light therapy sessions depends on the intensity of the light reaching the eyes. In the early 1980's, treatment consisted of two to three hours of exposure to two thousand five hundred lux. More recently it was found that thirty minutes exposure to ten thousand lux was equally effective, and less disruptive for many patients. The time of day when light therapy is administered is not critical for the beneficial effects to be perceived, which argues against the hypothesis that in the treatment of SAD, light therapy functions by resetting the body clock (the circadian rhythm).

Carol Watkins, M.D., Baltimore: 1998: About 70-80% of those with SAD are women. The most common age of onset is in one's thirties, but cases of childhood SAD have been reported and successfully treated. For every individual with full blown SAD, there are many more with milder "Winter Blues." The incidence of SAD increases with increasing latitude up to a point, but does not continue increasing all the way to the poles. There seems to be interplay between an individual's innate vulnerability and her degree of light exposure. For instance, one person might feel fine all year in Maryland but develop SAD when she moves to Toronto. Another individual may be symptomatic in Baltimore, but have few symptoms in Miami. Some individuals who work long hours inside office buildings with few windows may experience symptoms all year round. Some very sensitive individuals may note changes in mood during long stretches of cloudy weather. The individual measures the distance from her face to the light source. This measurement is important, and should be repeated daily for several days and occasionally after that. The light needs to strike one's eyes, but one does not need to look directly into the light source. It is fine to occasionally glance directly into the light. Many people read a book or eat breakfast while using the lights. Sitting still for 30 minutes to several hours is not an option for some people. For these people, the light visor is an option. Others are able to take one of the compact light boxes to work and use it for several hours. It is best to use the light source in an uninterrupted time block, but it can be helpful even with some interruptions. Long term treatment compliance is often more difficult than one might initially anticipate. This is an important reason to have a professional monitoring. Outdoor light, even when the sky is overcast, provides as much or more light than a light box. There has been a study showing improvement in SAD symptoms when individuals took a one-hour daily walk outside. Outside light is often brighter than the light boxes.

Helps in Out-Patient Trial: Random assignment study found 10,000 lux x 30min between 6 and 9 am improved depression by 27%. Depress Anxiety 2002;16(1):1-3