Seasonal Affective Disorder / Winter Blues


It’s December, and that means that in my neck of the woods in southwestern Canada we are getting a lot of dark, dreary, rainy days. The sun comes up after 7h30am and goes down around 4h30pm. Many of us long for a nice sunny vacation at this time of year to cope with the lack of light and the winter blues. "The winter blues" is mild compared to what those that suffer from Seasonal Affective Disorder (SAD) go through – severe depression in the winter time that then clears up in the spring when there is more light. Seasonal Affective Disorder is not something to be taken lightly, as it can impair one’s life to the point of not being able to function. People that are affected not only feel depressed, but frequently also feel lethargic, sleep excessively, are more sensitive to pain, tend to withdraw socially, crave sugar and often gain considerable weight.

Just as we need adequate dark time each night, we also need adequate light during the day for good hormone function. It seems that those who suffer from SAD need bigger differences in light and darkness for their hormonal systems to function appropriately, and interestingly enough, a far larger percentage of SAD sufferers than would be expected by chance, were born in the fall and the winter when there is less bright light during the day, and fewer light-time hours. I wonder if the lack of light exposure in the first few months of life has anything to do with developing SAD later. If we consider primitive humankind, it would make sense to time the birth of children to when food would be plentiful to encourage survival, just like in the rest of the animal world. And plentiful food usually occurs when there is more daylight and plants are growing. That said, snow-cover in the winter can be extremely bright, but most of us in our modernized world do not spend all day everyday outdoors when it is cold and snowy.

The hormones melatonin and cortisol and the neurotransmitters serotonin and probably dopamine are involved in SAD. Melatonin doesn’t seem to turn off adequately at dawn, causing morning drowsiness and oversleeping. Cortisol doesn’t seem to rise adequately in the morning which may contribute to lethargy during the day. Melatonin and cortisol influence serotonin function, and low serotonin levels are linked to depression in general. So gaining control over cortisol and melatonin is key to feeling better.

The most successful treatment method for SAD is using a full-spectrum fluorescent light box that provides about 10,000 lux of light each morning upon awakening for half an hour to an hour. Such a light box provides about 25 times more intense light than does most indoor lighting, and research shows that this boosts morning cortisol and suppresses melatonin. These light boxes can be purchased for home use, and they need to be used consistently each morning for at least three weeks before most people suffering from SAD will begin to feel better. It makes sense to me that the opposite side of the equation should be addressed too – complete darkness at night, and a good nine hours of darkness to boot. Black-out drapes are very helpful. Because SAD seems to be a circadian rhythm dysfunction, being very consistent with bedtimes and wake up times may help get the body clock back on track. So, turning out the lights at 10pm and using the light box at 7am consistently should work well.

As I have explained before, light and darkness play a fundamental role in our desire for carbohydrates. The later the lights are on at night, the higher our evening cortisol, the more we want to snack on carbs and sugar, the fatter we get. The cortisol connection may explain why SAD sufferers crave carbohydates and gain so much weight. Eating quality fats when wanting carbs may help suppress the cravings.

Morning exercise would probably also be extremely helpful, as exercise would not only boost morning cortisol, but would also reduce depression.

Related Tips
Is going to bed too late making you fat?
Melatonin, our rest and repair hormone
Cortisol, our stress hormone
Light pollution messes with our hormones

Online at Mood Disorders Society of Canada

Wiley TS and Formby B. Lights Out: Sleep, Sugar, and Survival Pocket Books, New York NY, 2000.

Lamont EW et al. The role of circadian clock genes in mental disorders Dialogues Clin Neurosci. 2007;9(3):333-42.

Sullivan B et al. Affective disorders and cognitive failures: a comparison of seasonal and nonseasonal depression. Am J Psychiatry. 2007 Nov;164(11):1663-7.

Lewy AJ et al.The phase shift hypothesis for the circadian component of winter depression Dialogues Clin Neurosci. 2007;9(3):291-300.

Pjrek E et al. Season of birth in siblings of patients with seasonal affective disorder : A test of the parental conception habits hypothesis Eur Arch Psychiatry Clin Neurosci. 2007 Sep 27;

Pjrek E et al. Seasonality of birth in seasonal affective disorder J Clin Psychiatry. 2004 Oct;65(10):1389-93

Willeit M et al. Enhanced Serotonin Transporter Function during Depression in Seasonal Affective Disorder Neuropsychopharmacology. 2007 Sep 19; epub ahead of print.

Thorn L et al. The effect of dawn simulation on the cortisol response to awakening in healthy participants Psychoneuroendocrinology 2004 Aug;29(7):925-30

Schwartz PJ et al. Serotonin hypothesis of winter depression: behavioral and neuroendocrine effects of the 5-HT(1A) receptor partial agonist ipsapirone in patients with seasonal affective disorder and healthy control subjects Psychiatry Res. 1999 Apr 19;86(1):9-28.

Thalén BE et al. Cortisol in light treatment of seasonal and non-seasonal depression: relationship between melatonin and cortisol. Acta Psychiatr Scand. 1997 Nov;96(5):385-94

Lewy AJ et al. Morning vs evening light treatment of patients with winter depression Arch Gen Psychiatry 1998 Oct;55(10):890-6

Eastman CI et al. Bright light treatment of winter depression: a placebo-controlled trial Arch Gen Psychiatry. 1998 Oct;55(10):883-9.

Swiecicki L et al. Platelet serotonin transport in the group of outpatients with seasonal affective disorder before and after light treatment, and in remission (in the summer) Psychiatr Pol. 2005 May-Jun;39(3):459-68.

Stain-Malmgren R et al. Platelet serotonergic functions and light therapy in seasonal affective disorder Psychiatry Res. 1998 May 8;78(3):163-72.

Copyright 2007 Vreni Gurd

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  1. Patricia Bates said,

    November 2, 2008 @ 5:19 pm

    Do you have this info in Spanish? If so, I need it ASAP. I am an RN who is helping with the large Hispanic communities in Oregon. I cannot imagine a bigger concern for those who came from hotter areas & settled here than ‘winter depression’. We are putting on a “Winter Wellness” workshop next week! Any info you can provide me in Spanish (& English too, because I speak only a little Spanish) would be greatly appreciated.
    Patrica Bates, RN, BSN, CURN (retired)

  2. Vreni said,

    November 3, 2008 @ 1:41 am

    Hi Patricia,

    I’m sorry, I don’t speak any Spanish and don’t have any info in Spanish. You are welcome to use this article in English if you want. And any of the references you can click on, which will provide more info for you. The book “Lights Out” (listed in the reference section) is fantastic reading – I highly recommend it.

    Good luck with your Wellness Workshop – perhaps you can sell black-out drapes and light boxes!

  3. mold inspection said,

    May 25, 2011 @ 3:12 am

    This is kind of a great resource that you are supplying and you give it away for free of charge.

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