It’s wintertime here in the Northern Hemisphere, and regardless of precipitation or how much snow there is on the ground, the light in the winter months changes compared to other seasons. These winter changes mean shorter days, early sunsets, and — for many — feeling lethargic and down. For some, the sad feeling that accompanies the season is more than the winter blues; it’s all-encompassing, and deeply affects their day to day existence. This is known as S.A.D., or Seasonal Affective Disorder, a form of seasonal depression
I grew up experiencing S.A.D. annually once I hit my late teens, and I did not know it had a name, or that there were easy solutions. I just thought something was wrong with me that come winter, I felt a sense of deep despair and emptiness that didn’t ebb until spring.
While the condition is in the press more and more, I wanted to write about it in case there are others here who aren’t using lightboxes but may benefit from them. Part of why I chased summer on my travels for a decade was to avoid the hopelessness that winter brought me. That and the warmer weather, always a plus.
These days, grounded indefinitely by a spinal CSF leak, I can’t follow the seasons that suit me best. Instead, I’ve taken to using a lightbox as set out below. This has helped me enjoy the cozy darkness, and I no longer experience those feelings of deep despair.
I hope it helps you too.
Symptoms of Seasonal Affective Disorder (S.A.D.)
The US National Institute of Mental Health defines S.A.D. as: “a type of depression characterized by a recurrent seasonal pattern, with symptoms lasting about 4−5 months out of the year.”
In most cases, S.A.D. symptoms start in the late fall or early winter, and disappear by spring. They are most prevalent during the gloomy, dark months of winter. There are “summer S.A.D.” patients too, though, who start feeling symptoms in spring, which then ebb by late autumn.
S.A.D. symptoms go beyond feeling down or stressed about the holidays, and mirror those of depressive disorders—the difference being that they occur at only a specific time of year.
The most common symptom is a despairing, “empty” and/or anxious mood that is:
- Present for most days and lasts most of the day
- Lasts for more than two weeks, and
- Impairs performance at work, at school, or in social or intimate relationships.
Additional symptoms of S.A.D. that mirror those of depression can include:
- Feelings of hopelessness or pessimism, irritability, frustration, or restlessness.
- Feelings of guilt, worthlessness, or helplessness.
- Loss of interest or pleasure in hobbies and activities.
- Decreased energy, fatigue, or feeling slowed down.
- Difficulty concentrating, remembering, or making decisions.
- Changes in sleep or appetite.
… and more.
For those that have winter-pattern S.A.D., some symptoms can include oversleeping (also called hypersomnia), weight gain due to cravings for sweet or carb-heavy foods and/or overeating, and social withdrawal (feeling like hibernating).
In contrast, the more rare summer-pattern S.A.D. patients have insomnia, poor appetite, anxiety, and “violent or aggressive behavior” per the NIH.
What causes seasonal depression?
In most cases, SAD begins in young adulthood, and arises from various factors associated with the changing seasons. It’s thought that a primary contributor is the diminished exposure to natural sunlight, a crucial element in regulating the body’s internal clocks. I’ve written at length about the body clock and circadian rhythms in my jet lag piece on Legal Nomads, and they play a big role in our health. So much so, that there’s a newer field of medicine dedicated to them: chronobiology.
Changes in the amount of sunlight not only affect our body clocks, which control our sleep-wake patterns, but also can disturb the production and function of different neurotransmitters that are associated with mood disorders, like serotonin or dopamine.
In addition, Norman Rosenthal, clinical professor of psychiatry at Georgetown Medical School and one of the first people to give S.A.D. a name, notes:
Some people with S.A.D. may have abnormalities in the genes responsible for serotonin transmission or for the sensitivity of the retina to light (perhaps because of abnormalities in the retinal pigment called melanopsin.
According to the Center for Addiction and Mental Health in Canada, risk factors for developing SAD include:
- Woman are more likely than men to be diagnosed with S.A.D..
- Geography: S.A.D. is more common in people who live either far north or far south of the equator.
- Age: young people are more likely to develop S.A.D.. The risk decreases with age.
- A family history of S.A.D. or other forms of depression also increases risk.
Almost 2 million people in the United Kingdom and more than 12 million across northern Europe are thought to suffer from S.A.D., according to the UK’s National Health Service. Adele recently did an interview where she said seasonal depression really affects her. (Stars! They’re just like us!)
In the United States, the number is around 5% of adults, though Rosenthal says that it’s closer 10% for those living near the northern border (i.e. the Canada).
In Canada, the seasonal subtype of depression represents 11% of all subjects with major depression, suggesting that S.A.D. is a significant public health concern.
The leading treatment for seasonal depression involves light therapy, adding more bright light during those gloomy winter days, especially first thing in the morning.
For people in areas that aren’t too cold, this can involve going outside and getting ‘bright light’ as much as possible. But let’s be honest, bright light isn’t that common in the winter months, plus it can be inconvenient to do so in trying to get out of the house first thing.
So the alternative is lightboxes, of which there are many on the market. While Rosenthal says that he prefers fluorescent lights, for those like me with a mast cell disorder or people who have very sensitive skin, fluorescent light can trigger flushing. I actually did not know that myself until I was diagnosed with a mast cell disorder; the practitioner who diagnosed me was the one to explain why I may be reacting to my lightbox. Sure enough, when I switched to LED I was fine.
Rosenthal also says that white light is better than blue light, and a foot squared (12 inch squared) sizing minimum is recommended.
Early lightbox studies showed that 2,500 lux (the measure for light intensity used in this field) were superior to ones that only emitted 300 lux. But many of those studies used a 2,500 lux light that was administered for 2-6 hours per day. Per the Psychiatric Times, later studies using 10,000 lux for 30 minutes in the morning yielded similar results to studies using 2,500 lux for two hours. While a linear relationship does not necessarily apply, since then 10,000 lux lightboxes have become the most common type sold and used in clinical practice.
Most people see improvements in mood from light therapy within 1-2 weeks of beginning treatment, and it’s recommended to keep doing it through the dark winter months.
A 2017 study found that 61% of participants who received bright light therapy over a 4-week period reached the definition of symptom remission. A 2005 meta-analysis of eight randomized controlled trials found that bright light therapy and dawn simulation are effective treatments for S.A.D.. A 2020 meta-analysis of 19 studies also showed that bright light therapy was effective compared with placebo, with an improvement in depression scores, though it said more high quality trials were needed.
Per Rosenthal, light therapy can also help reverse the gene abnormalities he noted above.
You want to place your lightbox pretty close to you; within a few feet is important. This is so that the white UV-free light gets right into your eyeballs. Don’t stare at it though, please. (If you have eye disorders, please also check with your ophthalmologist before beginning light therapy.) A kitchen countertop or desk works well, since you can still do whatever morning routine you have this way.
Given that I am primarily bedbound, and that my office where I work in the mornings during my limited ‘uptime’ is windowless, I use my lightbox daily regardless of season. Otherwise, I’d get no bright light in the morning. But I turn it on for longer in the winter (30 minutes) than in the summer months (15 minutes).
Summary of lightbox treatment for S.A.D.:
- You want to light-it-up in the morning, right after you get up.
- Find a lightbox with 10,000 lux strength, with white light not blue light.
- Use daily for a minimum of 15 minutes, preferably 30 minutes, especially in winter.
- Use it not too far away from your eyeballs.
A note about non-seasonal depression and light therapy
In 2016, a UBC study looked at four groups of non-seasonal depression patients. In the study, the groups were split into (1) those who received light therapy, (2) those who received the popular serotoninergic drug fluoxetine, (3) those who got a combo of light therapy and fluoxetine, or (4) those who got a placebo. Those who received light therapy responded better than those given the drug or placebo, and the combination of light therapy plus fluoxetine also showed positive results.
Why do I mention this? Because even if it’s a nonseasonal depression that you may be dealing with, it’s quite possible a lightbox can help support you better.
Lightbox options for Seasonal Affective Disorder
I have and use a VeriLux HappyLight. I have tried other brands, but this one works best for me, and I’ve bought it for family members as well. It’s also reasonably priced ($39.99 USD).
It’s a LED lamp, so not the fluorescents that Rosenthal says he prefers, but I can’t tolerate fluorescents as mentioned above.
Another option is the Carex Day-Light Classic Plus Bright Light Therapy Lamp, which is 12 inches across and the sizing that Rosenthal prefers. It’s more costly, but comes highly recommended by Wirecutter. Also 10,000 lux, and LED. It’s quite large so too cumbersome for me to lug around if I need to move it—but it may be better for you!
3) The Northern Light Technologies Boxelite-OS, which is in a 14 inch size, and also 10,000 lux. This Montreal-based company has been making lightboxes for 30 years, and they come highly recommended. This lightbox is built with input from the Center for Environmental Therapeutics (CET), an independent, non-profit professional organization dedicated to education and research on new environmental therapies.
CET’s Dr. Michael Terman collaborated with the company to build this large light surface (12 x 15 inches), with adjustable height and tilt. It has 10,000 lux served by fluorescents, and a seven-year unlimited warranty and a 60-day money-back guarantee.
While this brand was the first one I tried, especially as I was excited that it was local from Quebec, being that it is fluorescents I did not tolerate it.
(For those who want a smaller option: they also sell a rectangular lightbox: the BOXelite Light Therapy Lamp. )
Other treatments for seasonal depression
Other treatments for seasonal depression include exercise, meditation, ‘stress management’ (good luck with that), talk therapy, antidepressants, travelling to a sunnier place (also a privilege I know), and dietary changes.
For the diet, as the S.A.D. people crave sweets and starches, the recommendation is actually to try and choose them carefully, focusing on a diet rich in protein, vegetables, unprocessed foods, and more complex carbs than simple ones.
- Seasonal Affective Disorder (S.A.D.), Center for Addiction and Mental Health.
- Researchers Identify Best Times For Effective Light Therapy, American Psychiatric Association (2001)
- S.A.D., National Institute for Mental Health
- A guide to S.A.D., Norman Rosenthal (blog post)
- Defeating S.A.D. (Seasonal Affective Disorder): A Guide to Health and Happiness Through All Seasons by Norman Rosenthal (book published in 2023)