A Light on Seasonal Affective Disorder: Definition, Treatment, & Prevention | Image shows person in winter with hood up facing the forest

A Light on Seasonal Affective Disorder: Definition, Treatment, & Prevention

Oct 18, 2018

By Henry Emmons, MD

Our annual journey around the sun has crossed the threshold that creates a mild sense of dread in many people—winter is coming. The days are now shorter than the nights, and if you live north of a line going through Atlanta, you are probably noticing a change in your biology. Your body wants you to hibernate. Most of us don’t actually hibernate, and probably wouldn’t feel good if we did, but living out of sync with nature’s rhythms comes at a cost.

You may just feel a little sluggish, want to sleep more, crave comfort foods, or have a harder time getting to a gym. Or, you may feel something more—a specific form of depression known as seasonal affective disorder (known by the apt acronym SAD).

What is Seasonal Affective Disorder?

Seasonal affective disorder refers to a form of depression that occurs at a specific time of year. For most people, that means the winter, though there are subsets that occur in the spring or summer. Look for a post on the warmer seasons later, this one will explore winter depression.

SAD is primarily a problem of circadian rhythm, your system's natural 24-hour cycle. That cycle is reset each day via light-sensitive parts of the retina that send a signal to the brain, letting it know when the sun is rising or setting. A tiny area of the brain known as the pineal gland is the master time-keeper, telling every other cell in the body how to set their own clock. Those cells in turn use that information to do the parts of their jobs that are time-sensitive, such as when to fall asleep and wake up; what times of day are meant for the highest energy; and what times we should begin to unwind and prepare for bed. The hormone systems in the body are also tied to this timekeeper, releasing their hormones at various amounts through the day to help encourage that daily rhythm.

Cortisol, the main stress hormone, is strongly influenced by this rhythm, and that may be one of the main reasons why some people become depressed in winter. Some forms of depression seem to be primarily an issue of the brain and the adrenals no longer communicating effectively with one another. The body gets confused.

The pineal gland also releases melatonin in relation to your exposure to light, telling you when to go to sleep. During those long nights of winter, it releases a lot more melatonin: “Hibernate, hibernate!” Unfortunately, that may come at the expense of serotonin—it’s as if the body steals from one storeroom to supply the other. These shifts can result in feeling both excessively tired and depressed. Ugh.

Seasonal Affective Disorder Symptoms

SAD is similar to what used to be known as “melancholic depression.” Before so many people suffered from stress-related depression, this was what most people thought of when they used the term depression. It’s the kind of depression where it’s hard to get out of bed, hard to get off the couch, hard to go to work or school, hard to think. It’s described as “slogging through mud” or feeling like you’re carrying a lot of extra weight.

Common symptoms of SAD

  • MOOD may be sad or depressed, but is often just flat or suppressed.
  • SLEEP is almost always affected. Often, the amount of sleep is excessive. A subset of people become super sleepy in the early evening, around 7-8 PM. If they don’t go to sleep that early, then they may stay up far later, get less overall sleep, and really struggle to get up in the morning.
  • ENERGY is nearly always affected. Most people feel sluggish and lethargic.
  • MOTIVATION is often low. Unfortunately, this makes it hard to exercise, which is one of the best forms of prevention and treatment for SAD.
  • LOSING INTEREST in things or getting less pleasure from activities is common.
  • CONCENTRATION is often reduced.
  • SUICIDAL IDEATION can occur, but it is less likely with SAD unless there is something more going on.

Seasonal Affective Disorder Treatment

SAD is better prevented than treated. If prevention strategies start by October, SAD can be prevented for many individuals. There are four strategies that I usually recommend for prevention. Put them into practice and you can improve your chances of getting through the winter intact.

1. Light Therapy

Remember the root cause of SAD: the length of days. You want to trick your body into thinking that the days are longer than they really are. To do this, use a bright light device and greatly limit your exposure to light in the last couple of hours before bed. The last thing you want is to push your melatonin release back so far that you can’t get to sleep when you want to go to bed, and then it feels impossible to wake up at your desired time.

The goal with light therapy is to trick your brain into thinking that the sun is rising much earlier than it is. That means that you have to use a very bright light, and it needs to be early in the day. I recommend 20-30 minutes first thing in the morning (preferably before 8 AM).

You'll need a high quality light that is bright enough (equivalent to 10,000 lux). You may have heard of a "seasonal affective disorder light box" or a "seasonal affective disorder lamp." Not all are created equal, so talk to your doctor for any recommendations.

You'll need to sit close to your light (typically 1 ½ to 2 feet) to get the full benefits. You do not need to stare into the light. You just need it in front of you, with your eyes open, so that the light hits the back of your retinas. You can do something else, like reading or eating breakfast. It’s a good idea to get a portable product, ideally one with batteries, so that you can take it to work or elsewhere if you don’t have time to use it at home.

Bonus dose: It can also be helpful to use your light again in the late afternoon, especially if you get really sleepy between 6-8 PM. That’s because melatonin is released within an hour or two after sunset, and that happens so early for some of us that you might want to go to bed right after dinner. Assuming that you don’t head to bed so early, you might notice that when your desired bedtime of 10 or 11 PM arrives, you aren’t sleepy. Melatonin only lasts a few hours, so it is gone by then and you don’t have a signal to go to sleep. If this happens to you, use the light again for 15-20 minutes in the late afternoon, around 5-6 PM.

For much more information on light therapy, and to learn about the different seasonal affective disorder lamps, see Dr. Culbert’s article

2. Regulate Your Sleep

Treat your bedtime like you would a kid's. Go to bed at nearly the same time every day and be especially mindful of getting up at the same time each day—even on weekends. Sleep in by no more than one hour. A strict sleep schedule may not sound like fun, but it does wonders to help regulate your circadian rhythm. If you need help with this, consider getting a dawn simulator like the Philips Wake Up Light.

3. Exercise Regularly

Ironically, the best kind of exercise for SAD is on the more vigorous side, so don’t wait until you have symptoms of sluggishness or depression to start. Start now and don’t stop. Do moderately vigorous aerobic activity for at least 30 minutes 4-5 days per week. Even better, add some strength training and/or interval work a couple times per week. Go to our NMH Natural Foundations category for more info on how to create your ideal movement plan.

4. Supplement Wisely

I recommend three supplements, taken in the morning, to support low mood and energy:

  • Activated B-Complex (Resilient RemediesTM Activate). B vitamins can help with energy, motivation and mood by making it easier to keep up with the demand for serotonin and dopamine. 

  • Adaptogen herbs (Resilient RemediesTM Adapt). Adaptogens are broadly beneficial, very safe, and well-tolerated herbs that support major systems in the body, including the adrenal-stress system. Most people find them gently energizing and supportive of mood without causing agitation.

  • Vitamin D3 (Resilient RemediesTM Illuminate): I usually recommend 5000 IU, but if you know that your vitamin D levels are normal, then 2000 IU should suffice.

There are more options if symptoms of SAD persist. Vigorous exercise can be stepped up even more. Additional supplements to support the neurotransmitters of mood, energy, and motivation can also be considered. In my practice, I usually start with 2 capsules daily of Energized Mood. If that’s not helping within one week, then I have my patients go up to 4 capsules daily. It's an activating supplement, so I encourage folks to take it in the morning. 


Antidepressant medications may be another route for individuals. It's a good idea when symptoms are so strong that they greatly impact functioning, or if the above measures have not been sufficient. Most physicians prescribe SSRIs to begin with. They often help, especially with stress and anxiety symptoms, but since they’re not typically energizing, they may not do much for the sluggishness, sleepiness, or lack of motivation. If those symptoms linger after being on an antidepressant for a few weeks, talk to your doctor about something more activating, or consider adding the above supplements. There’s evidence that adding SAMe to an antidepressant, for example, can boost the effectiveness of the medication.

Do It Again!

Whatever works for you, my recommendation is to keep doing it until at least April. Then pack it all away for the summer, but bring it out again by early next October!



*Note: Some of the supplements discussed in this article can cause side effects, but many people tolerate them much better than prescription medications. They are generally considered safe, however, they should not be started without your doctor’s knowledge and supervision. If you are taking medication already, be sure to talk with your doctor before adding any of these items. If you are considering going off medication, remember never to stop your medication suddenly—always consult with your doctor about how to safely taper off any psychiatric medication. See terms (link terms).

**These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. 




SAD Light Therapy

Learn when to use your therapy lamp, recommended duration, and specific features your lamp should offer. Read more.





Discover your Resilience Type with the Resilience Quiz

After completing the quiz, you can get your free tailored mini-course, full of integrative practices and supplement ideas to help you reclaim your most resilient self.

Learn more
Resilience Type Quiz: A person wearing a white t-shirt and green pants is shown holding up falling beams.

Sleep Peacefully in Spring and Summer

Jun 01, 2023

Which Supplement Should I Take to Replace Relax Powder?

May 30, 2023

What is Equanimity?

Mar 09, 2023

Why Nutrition is Important: Understanding Food as Information

Nov 17, 2022

Helpful support delivered right to your inbox.

We’ll make your journey to resilience easier. Join our weekly newsletter for integrative tools to help you reclaim joy and calm more naturally.


This content is for informational and educational purposes only. It is not intended to provide medical advice and is not a replacement for advice and treatment from a medical professional. Consult your doctor or other qualified health professional regarding specific health questions. Individuals providing content to this website take no responsibility for possible health consequences of any person or persons reading or following the information in this educational content. It is also essential to consult your physician or other qualified health professional before beginning any diet change, supplement, or lifestyle program.