Seasonal Affective Disorder

Also indexed as: SAD, Seasonal Depression, Winter Depression

Many people experience changes in mood with the change of season. Seasonal affective disorder (SAD) is an extreme form of these common seasonal mood cycles. How seasonal changes cause depression is unknown, but most of the research into mechanisms and treatment has focused on changes in levels of the brain chemicals melatonin and serotonin in response to changing lengths of exposure to light and darkness.

Checklist for Seasonal Affective Disorder

Rating Nutritional Supplements Herbs
2Stars   St. John’s wort
1Star 5-HTP
Vitamin D		  
3Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1Star An herb is primarily supported by traditional use, or the herb or supplement has little scientific support and/or minimal health benefit.

What are the symptoms of seasonal affective disorder? SAD is characterized by typical symptoms of depression, such as sadness, hopelessness, and thoughts of suicide (in some cases), and “atypical” depressive symptoms such as excessive sleep, lethargy, carbohydrate cravings, overeating, and weight gain. The symptoms usually occur the same time of year, typically fall and winter, and disappear with the onset of spring and summer.

How is it treated? Conventional treatment includes daily exposure to full-spectrum fluorescent light (sometimes provided by special light boxes), getting outside during the day as much as possible, and the use of a “gradual awakening” light, which is programmed to slowly increase in intensity in the morning.

Dietary changes that may be helpful: Cravings for simple carbohydrates are increased in SAD, and women diagnosed with this form of winter depression have been found to eat more carbohydrates, both sweets and starches, than do healthy women. These women also report eating in response to emotionally difficult conditions, anxiety, depression, and loneliness more frequently than healthy women, but eating patterns associated with SAD are distinct from those of women with eating disorders.1

People with SAD process sugar differently in winter compared with summer or after light therapy in winter.2 Changes in neurotransmitters that may affect cravings also occur in women with SAD.3 Because consumption of carbohydrates can influence neurotransmitter levels,4 some authorities have speculated that eating simple carbohydrates may be a form of self-medication in people with SAD. A review of the research on diet and mood found that, while eating simple carbohydrates in reaction to depressed mood does bring about a temporary lift in mood, other evidence suggests that long-term control of negative moods is, for some people, best achieved by eliminating simple carbohydrates from the diet.5 No research has yet been conducted, however, to evaluate the benefits of a diet low in simple carbohydrates (or any other dietary intervention) for people with SAD.

Lifestyle changes that may be helpful: Exercise can ease depression and improve well being, in some cases as effectively as antidepressant medications.6 One study found that both one hour of aerobic exercise three times per week and the same amount of anaerobic exercise were significantly and equally effective in reducing symptoms of depression.7 In a preliminary study of women with SAD, exercise while exposed to light was more likely to be associated with fewer seasonal depressive symptoms than was exercise performed with little light exposure.8 A controlled study of 120 indoor employees used relaxation training as the placebo in a study of fitness training, light exposure, and winter depressive symptoms. Fitness training was performed two to three times per week while exposed to either bright light (2,500–4,000 lux) or ordinary light (400–600 lux). Compared to relaxation, exercise in bright light improved general mental health, social functioning, depressive symptoms, and vitality, while exercise in ordinary light improved vitality only.

Nutritional supplements that may be helpful: L-tryptophan is the amino acid used by the body to manufacture serotonin. Several trials, some controlled, have shown that experimentally inducing a tryptophan deficiency in people with SAD who are in remission brings about a relapse of depressive symptoms.9 10 11 12 13 This suggests that supplemental L-tryptophan might be helpful in SAD. In small, preliminary trials, 4 to 6 grams of L-tryptophan given in divided amounts daily was as effective as light therapy14 15 and more effective than placebo.16 L-tryptophan may be of particular use in people with winter depression who do not benefit from light therapy. In a preliminary trial, people with SAD who responded only partially or not at all to bright light therapy were given 1,000 mg of L-tryptophan three times daily in addition to 10,000 lux light therapy for 30 minutes every morning. Sixty-four percent of them had significant improvement in depressive symptoms while receiving both L-tryptophan and bright light therapy.17 L-tryptophan is currently available by prescription only.

5-HTP is a substance related to L-tryptophan that increases serotonin production and has shown antidepressant activity.18 It may also be useful in the treatment of SAD, but there is currently no research testing this possibility.

Vitamin D is well known for its effects on helping to maintain normal calcium levels, but it also exerts influence on the brain, spinal cord, and hormone-producing tissues of the body that may be important in the regulation of mood.19 A double-blind controlled study found that mood improved in healthy people without SAD who received 400 or 800 IU per day of vitamin D for five days in late winter.20 However, no difference in vitamin D levels has been observed between people with seasonal depression and those without,21 22 and the antidepressant activity of light therapy has been shown to be independent of changes in levels of vitamin D.23 A large study of women found that supplementation with 400 IU per day of vitamin D had no impact on the incidence of winter depression.24 Any benefits of vitamin D on SAD remain unproven.

Depression can be one of the first symptoms of vitamin B12 deficiency.25 Vitamin B12, in the form of cyanocobalamin, given orally in the amount of 1,500 mcg three times daily to patients with seasonal depression, showed no superiority over placebo in a double-blind trial.26 Vitamin B12 cannot be recommended for the treatment of SAD.

Melatonin is a hormone produced in the body in response to the rhythms of light and darkness. Changes in melatonin levels are believed to be an important factor in seasonal depression. Supplementation with melatonin, however, has been ineffective when taken at night or in the morning.27 Melatonin may even reverse the benefits of light therapy in people with SAD.28 A small, double-blind study, however, found that 125 mcg of melatonin taken both 8 and 12 hours after awakening was effective for reducing depression’s symptoms.29

Are there any side effects or interactions? Refer to the individual supplement for information about any side effects or interactions.

Herbs that may be helpful: St. John’s wort, an herb well known for its antidepressant activity,30 has been examined for its effectiveness in treating SAD. In a preliminary trial, patients with seasonal depression were given 900 mg per day of St. John’s wort in addition to either bright light (3,000 lux for two hours) or a dim light (300 lux for two hours) placebo.31 Both groups had significant improvement in depressive symptoms, but there was no difference between the groups. The authors concluded that St. John’s wort was beneficial with or without bright light therapy, but a placebo effect from the herb cannot be ruled out in this study. Another preliminary study asked 301 SAD patients to report the changes in their symptoms resulting from the use of St. John’s wort at 300 mg three times daily.32 Significant overall improvement was reported by these patients. Some of the subjects used light therapy in addition to St. John’s wort. They reported more improvement in sleep, but overall improvement was not significantly different from those using St. John’s wort alone. Double-blind research is needed to confirm the usefulness of St. John’s wort for treating SAD.

Are there any side effects or interactions? Refer to the individual herb for information about any side effects or interactions.

Other integrative approaches that may be helpful: Diminished sunlight exposure in winter contributes to changes in brain chemistry and plays a role in seasonal mood changes. Artificial lights have been widely used to increase light exposure during winter months. Many studies show the benefit of light therapy in the treatment of SAD.33 34 35 36 In a controlled trial, 96 patients with SAD were treated with light at 6,000 lux for 1.5 hours in either morning or evening, or with a sham negative ion generator, which was used as the placebo. After three weeks of treatment, morning light produced complete or near-complete remission for 61% of patients, while evening light helped 50%, and placebo helped 32%.37 Another study similarly found morning light to have more antidepressant activity than evening light for people with SAD. This study also found that patterns of melatonin production were altered in seasonal depression, and that morning light therapy shifted this pattern toward those of control subjects who did not have seasonal depression.38 Blood flow to certain regions of the brain was measured after light therapy and was increased in seasonal depression patients who benefited from the light therapy. The increase in regional brain blood flow did not occur in those patients who did not respond to the light therapy.39 Light therapy begun prior to the onset of winter depression appears to have a preventive effect in people susceptible to SAD.40

A review of clinical trials of light therapy for SAD concluded that the intensity of the light is related to the effectiveness of the treatmnent.41 A higher response rate was seen in trials where light intensity was greater, compared with trials that used light therapy of lower intensity. Red and potentially harmful ultraviolet wavelengths are not necessary for a response to light therapy.42

A study of the adverse side effects from high-intensity light therapy found them to be common, mild and brief. Among people who underwent brief treatment with 10,000 lux, 45% experienced side effects such as headaches and eye and vision changes. Described as mild and temporary, they did not interfere with treatment.43

Dawn simulation is a form of light therapy involving gradually increasing bedside light in the morning. In a comparison study, dawn simulation using 100–300 lux for 60–90 minutes every morning improved symptoms of SAD similarly to bright light therapy using 1,500–2,500 lux for two hours every morning.44

A negative ionizer is a device that emits negatively charged particles into the air. Negative air ionization may be useful in treating SAD. One double-blind trial compared the benefits of high-density negative ionization, providing 2.7 million ions per cubic centimeter, and low-density negative ionization, providing 10,000 ions per cubic centimeter, for people with SAD. Atypical depressive symptoms improved by 50% or more for 58% of patients receiving the high-density ionization for 30 minutes daily, while only 15% of those receiving low-density ionization had 50% or greater improvement. There were no side effects, and all of the patients who responded to the therapy relapsed when ionization was discontinued.45 In another controlled trial, high-density ionization was found equally as effective as light therapy, and both were significantly more effective than low-density ionization.46

References:

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2. Krauchi K, Keller U, Leonhardt G, et al. Accelerated post-glucose glycaemia and altered alliesthesia-test in Seasonal Affective Disorder. J Affect Disord 1999;53:23–6.

3. Danilenko KV, Putilov AA, Russkikh GS, et al. Diurnal and seasonal variations of melatonin and serotonin in women with seasonal affective disorder. Arctic Med Res 1994;53:137–45.

4. Blum I, Vered Y, Graff E, et al. The influence of meal composition on plasma serotonin and norepinephrine concentrations. Metabolism 1992;41:137–40.

5. Christensen L. Effects of eating behavior on mood: a review of the literature. Int J Eat Disord 1993;14:171–83 [review].

6. Blumenthal JA, Babyak MA, Moore KA, et al. Effects of exercise training on older patients with major depression. Arch Intern Med 1999;159:2349–56.

7. Martinsen EW, Hoffart A, Solberg O. Comparing aerobic with nonaerobic forms of exercise in the treatment of clinical depression: a randomized trial. Compr Psychiatry 1989;30:324–31.

8. Groom KN, O’Connor ME. Relation of light and exercise to seasonal depressive symptoms: preliminary development of a scale. Percept Mot Skills 1996;83:379–83.

9. Neumeister A, Habeler A, Praschak-Rieder N, et al. Tryptophan depletion: a predictor of future depressive episodes in seasonal affective disorder? Clin Psychopharmacol 1999;14:313–5.

10. Neumeister A, Turner EH, Matthews JR, et al. Effects of tryptophan depletion vs catecholamine depletion in patients with seasonal affective disorder in remission with light therapy. Arch Gen Psychiatry 1998;55:524–30.

11. Neumeister A, Praschak-Rieder N, Besselmann B, et al. Effects of tryptophan depletion in fully remitted patients with seasonal affective disorder during summer. Psychol Med 1998;28:257–64.

12. Neumeister A, Praschak-Rieder N, Besselmann B, et al. Effects of tryptophan depletion on drug-free patients with seasonal affective disorder during a stable response to bright light therapy. Arch Gen Psychiatry 1997;54:133–8.

13. Lam RW, Zis AP, Grewal A, et al. Effects of rapid tryptophan depletion in patients with seasonal affective disorder in remission after light therapy. Arch Gen Psychiatry 1996;53:41–4.

14. Ghadirian AM, Murphy BE, Gendron MJ. Efficacy of light versus tryptophan therapy in seasonal affective disorder. J Affect Disord 1998;50:23–7.

15. McGrath RE, Buckwald B, Resnick EV. The effect of L-tryptophan on seasonal affective disorder. J Clin Psychiatry 1990;51:162–3.

16. McGrath RE, Buckwald B, Resnick EV. The effect of L-tryptophan on seasonal affective disorder. J Clin Psychiatry 1990;51:162–3.

17. Lam RW, Levitan RD, Tam EM, et al. L-tryptophan augmentation of light therapy in patients with seasonal affective disorder. Can J Psychiatry 1997;42:303–6.

18. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Alternative Med Rev 1998;3:271–80.

19. Stumpf WE, Privette TH. Light, vitamin D and psychiatry. Role of 1,25 dihydroxyvitamin D3 (soltriol) in etiology and therapy of seasonal affective disorder and other mental processes. Psychopharmacology (Berl) 1989;97:285–94 [review].

20. Lansdowne AT, Provost SC. Vitamin D3 enhances mood in healthy subjects during winter. Psychopharmacology (Berl) 1998;135:319–23.

21. Oren DA, Schulkin J, Rosenthal NE. 1,25 (OH)2 vitamin D3 levels in seasonal affective disorder: effects of light. Psychopharmacology (Berl) 1994;116:515–6.

22. Partonen T, Vakkuri O, Lamberg-Allardt C, Lonnqvist J. Effects of bright light on sleepiness, melatonin, and 25-hydroxyvitamin D(3) in winter seasonal affective disorder. Biol Psychiatry 1996;39:865–72.

23. Partonen T, Vakkuri O, Lamberg-Allardt C, Lonnqvist J. Effects of bright light on sleepiness, melatonin, and 25-hydroxyvitamin D(3) in winter seasonal affective disorder. Biol Psychiatry 1996;39:865–72.

24. Harris S, Dawson-Hughes B. Seasonal mood changes in 250 normal women. Psychiatry Res 1993;49:77–87.

25. Fine EJ, Soria ED. Myths about vitamin B12 deficiency. Southern Med J 1991;84:1475–81.

26. Oren DA, Teicher MH, Schwartz PJ, et al. A controlled trial of cyanocobalamin (vitamin B12) in the treatment of winter seasonal affective disorder. J Affect Disord 1994;32:197–200.

27. Wirz-Justice A, Graw P, Krauchi K, et al. Morning or night-time melatonin is ineffective in seasonal affective disorder. J Psychiatr Res 1990;24:129–37.

28. Rosenthal NE, Sack DA, Jacobsen FM, et al. Melatonin in seasonal affective disorder and phototherapy. J Neural Transm Suppl 1986;21:257–67.

29. Lewy AJ, Bauer VK, Cutler NL, Sack RL. Melatonin treatment of winter depression: a pilot study. Psychiatry Res 1998;77:57–61.

30. Kim HL, Streltzer J, Goebert D. St. John’s wort for depression: a meta-analysis of well-defined clinical trials. J Nerv Ment Dis 1999;187:532–8 [review].

31. Martinez B, Kasper S, Ruhrmann S, Moller HJ. Hypericum in the treatment of seasonal affective disorders. J Geriatr Psychiatry Neurol 1994;7:S29–33.

32. Wheatley D. Hypericum in seasonal affective disorder (SAD). Curr Med Res Opin 1999;15:33–7.

33. Lee TM, Chan CC. Dose-response relationship of phototherapy for seasonal affective disorder: a meta-analysis. Acta Psychiatr Scand 1999;99:315–23 [review].

34. Lewy AJ, Bauer VK, Cutler NL, et al. Morning vs evening light treatment of patients with winter depression. Arch Gen Psychiatry 1998;55:890–6.

35. Eastman CI, Young MA, Fogg LF, et al. Bright light treatment of winter depression: a placebo-controlled trial. Arch Gen Psychiatry 1998;55:883–9.

36. Lingjaerde O, Foreland AR, Dankertsen J. Dawn simulation vs. lightbox treatment in winter depression: a comparative study. Acta Psychiatr Scand 1998;98:73–80.

37. Eastman CI, Young MA, Fogg LF, et al. Bright light treatment of winter depression: a placebo-controlled trial. Arch Gen Psychiatry 1998;55:883–9.

38. Lewy AJ, Bauer VK, Cutler NL, et al. Morning vs evening light treatment of patients with winter depression. Arch Gen Psychiatry 1998;55:890–6.

39. Vasile RG, Sachs G, Anderson JL, et al. Changes in regional cerebral blood flow following light treatment for seasonal affective disorder: responders versus nonresponders. Biol Psychiatry 1997;42:1000–5.

40. Partonen T, Lonnqvist J. Prevention of winter seasonal affective disorder by bright-light treatment. Psychol Med 1996;26:1075–80.

41. Lee TM, Chan CC. Dose-response relationship of phototherapy for seasonal affective disorder: a meta-analysis. Acta Psychiatr Scand 1999;99:315–23 [review].

42. Lee TM, Chan CC, Paterson JG, et al. Spectral properties of phototherapy for seasonal affective disorder: a meta-analysis. Acta Psychiatr Scand 1997;96:117–21 [review].

43. Kogan AO, Guilford PM. Side effects of short-term 10,000-lux light therapy. Am J Psychiatry 1998;155:293–4.

44. Lingjaerde O, Foreland AR, Dankertsen J. Dawn simulation vs. lightbox treatment in winter depression: a comparative study. Acta Psychiatr Scand 1998;98:73–80.

45. Terman M, Terman JS. Treatment of seasonal affective disorder with a high-output negative ionizer. J Altern Complement Med 1995;1:87–92.

46. Terman M, Terman JS, Ross DC. A controlled trial of timed bright light and negative air ionization for treatment of winter depression. Arch Gen Psychiatry 1998;55:875–82.