Some of us just weren't meant for the cold temperatures and darkness of winter. The wintertime blues are normal -- and often curable with some company and a hot chocolate. But there's a difference between a low mood and a months-long episode of depression that nothing seems to lift. That season-specific depression is known as seasonal affective disorder (the appropriately abbreviated SAD).
You might not know that SAD can also happen in the summer, although symptoms are slightly different. Weight gain, oversleeping and loss of libido are associated with winter depression, while summer depression symptoms include weight loss, insomnia and increased sex drive [source: Mayo Clinic].
People often use "seasonal affective disorder" to describe being tired and cranky during winter, but SAD can be severe to the point of suicidal thoughts.
There are several things a person prone to seasonal affective disorder can do to ward off symptoms. For many people, light therapy in the wintertime has proven benefits. Although no one is sure what causes SAD, one theory is that lack of light may play on the brain's neurotransmitters. Upping your exposure can counteract those effects.
Exercise can also mitigate the symptoms of depression, especially cardio exercise and yoga, which relies on deep breathing and is known to modify your stress response.
When these efforts don't work, a doctor may describe antidepressant medication. But some people wonder if the secret to quashing seasonal depression is as simple as a trip to the grocery store. Is there evidence to back it up? Let's take a look.
What to Stock Up On
Complex carbohydrates: Many people crave carbs when they're depressed -- especially when they're struggling with wintertime SAD. Whether it's a chemical cause or a learned behavior is unclear, but there's something about a big piece of chocolate cake that promises sweet relief. Carbs affect the body's serotonin levels, which makes you feel good. But be careful with the foods you choose -- simple carbs can cause a spike in blood sugar and then a crash. Complex carbs keep things nice and steady, so stick to foods like oatmeal and whole-wheat bread [source: WebMD].
Omega-3s: Researchers have been investigating the connection between omega-3 fatty acids and heart health, but there have been some interesting studies on omega-3s and depression, as well.
There are different types of omega-3 fatty acids. Your body can't make its own -- you have to know what to put in your mouth to get them. The two omega-3 fatty acids with the biggest health benefits are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), found in fish such as sardines, salmon and halibut.
What do omega-3s do? Among several other important functions, such as keeping blood from clotting too much, omega-3s help with brain and behavioral function [source: University of Maryland Medical Center]. People with an omega-3 deficiency exhibit poor memory, poor concentration, mood swings, fatigue and depression. So if depression is a symptom of deficiency, researchers thought these fatty acids could be a possible cure for it.
If you look at the studies examining the role of omega-3s in improving depression symptoms, you won't find a clear answer. Some studies have found that omega-3 supplements in addition to medications help people with depression and bipolar disorder. But those findings aren't consistent [source: University of Maryland Medical Center]. If you decide to take a supplement, pick one with mostly EPA -- a meta-analysis showed that to be the most effective [source: Raison].
Vitamin D: Without vitamin D, your bones get soft and weak, your immune system falls apart and your muscle strength is reduced. Vitamin D deficiency may also be linked to depression in older people [source: WHFoods].
One way we get vitamin D is from fortified foods, such as milk and cereal -- few foods contain it naturally, although salmon and tuna are good bets (get your omega-3s and vitamin D in one sitting!). The other way we get it is from the sun.
Exposure to the sun's UVB rays triggers your body to produce vitamin D, but it's not a perfect system. People with dark skin don't make the same amount of vitamin D, for example, and neither do people who live far away from the equator. Overweight and older people also have lower levels of vitamin D [source: Harvard School of Public Health].
Since seasonal affective disorder is thought to be connected to a lack of exposure to light, researchers are interested in the vitamin that's made from sunlight. Like with omega-3s, there isn't conclusive evidence indicating that eating foods high in vitamin D will help symptoms of seasonal affective disorder. But the research is promising, and there's a good chance you're deficient anyway, according to the Harvard School of Public Health.
Are supplements effective?
Now that you have your grocery shopping list in order, let's examine supplements.
- Melatonin: The neurotransmitter melatonin stabilizes your internal clock. That's why people with jet lag, for example, are advised to take a supplement or enjoy some melatonin-producing foods such as raspberries, tart cherries and almonds [source: Kasselik]. Some people also report that melatonin helps their depression symptoms, but others say the supplement actually makes their depression worse. This isn't one to try without talking to your doctor. What melatonin definitely does help with is insomnia, so if your sleep patterns are disturbed by seasonal affective disorder or depression, it may be helpful for you.
- Selenium: Low levels of the mineral selenium have been reported in people with depressive symptoms, but there is no clear correlation between the two -- and no evidence that low selenium actually causes mood disorders [source: Gao et al.]. But if you'd like to add a handful of Brazil nuts or a supplement to your diet to up your intake, it probably won't hurt.
- 5-HTP: Since it's believed that an imbalance in serotonin levels may be responsible for depression, scientists have been looking into factors that affect serotonin to find out how to influence its production. 5-HTP, which is made after you ingest tryptophan-rich foods like turkey, is converted into serotonin [source: University of Maryland Medical Center]. Can 5-HTP help depression in the same way antidepressants that affect serotonin do? Following our theme, the answer is unclear. There just isn't enough research to say.
- SAMe: You won't find it in foods, but the supplement SAMe has strong support. A 2002 analysis of available studies showed that SAMe provided symptom relief for depressed people. A more recent study, in 2010, showed that when SAMe was added to antidepressant treatment for people with major depression, there was clinically significant improvement [source: Nelson]. This is cheery news for people who don't respond well to antidepressant treatment alone.
What can we take from these findings? Modifying your diet to include more omega-3 rich foods and vitamin D, plus swapping out simple carbs for complex ones, may brighten your mood -- and it will definitely improve your health. And while there are high hopes for certain supplements, there hasn't been enough research done to justify their use, in many cases.
If you are dealing with seasonal affective disorder, talk to a health professional about what you can do. Even though supplements are naturally occurring substances, they can interact badly with certain medications and conditions, so make sure to bring them up if you use them.
- CBS News. "Foods to Cure the Winter Blues." Feb. 25, 2010. (Sept. 5, 2012) http://www.cbsnews.com/2100-500165_162-6223437.html
- Gao, Sujuan et al. "Selenium level and depressive symptoms in a rural elderly Chinese cohort." BMC Psychiatry. July 3, 2012. (Sept. 5, 2012) www.biomedcentral.com/1471-244X/12/72/abstract
- Harvard School of Public Health. "Vitamin D and Health." (Sept. 5, 2012) http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/vitamin-d/index.html
- Health.com. "7 Signs of Seasonal Affective Disorder." (Sept. 5, 2012) http://www.health.com/health/gallery/0,,20309270,00.html
- Kasselik, Maren. "6 Foods for Better Sleep." Men's Health. Nov. 9, 2011. (Sept. 5, 2012) http://news.menshealth.com/6-foods-for-better-sleep/2011/11/09/
- MedlinePlus. "Melatonin." Last reviewed Dec. 24, 2011. (Sept. 5, 2012) http://www.nlm.nih.gov/medlineplus/druginfo/natural/940.html
- National Alliance on Mental Illness. "Seasonal Affective Disorder." Last reviewed February 2004. (Sept. 5, 2012) http://www.nami.org/Content/ContentGroups/Helpline1/Seasonal_Affective_Disorder_%28SAD%29.htm
- Nelson, J. Craig. "S-Adenosyl Methionine (SAMe) Augmentation in Major Depressive Disorder." The American Journal of Psychiatry. Aug. 1, 2010. (Sept. 5, 2012) http://ajp.psychiatryonline.org/article.aspx?Volume=167&page=889&journalID=13
- Parker-Pope, Tara. "Study Shows SAMe May Ease Depression." The New York Times. Aug. 31, 2010. (Sept. 5, 2012) http://well.blogs.nytimes.com/2010/08/31/study-shows-same-may-ease-depression/
- Raison, Charles. "Can omega-3 fatty acids help prevent depression?" CNN.com. Nov. 1, 2011. (Sept. 5, 2012) http://www.cnn.com/2011/HEALTH/expert.q.a/11/01/fatty.acid.depression.raison/index.html
- Sacks, Frank. "Ask the Expert: Omega-3 Fatty Acids." Harvard School of Public Health Nutrition Source. (Sept. 5, 2012) http://www.hsph.harvard.edu/nutritionsource/questions/omega-3/index.html
- University of Maryland Medical Center. "Omega-3 fatty acids." Last reviewed May 10, 2011. (Sept. 5, 2012) http://www.umm.edu/altmed/articles/omega-3-000316.htm
- University of Maryland Medical Center. "5-Hydroxytryptophan (5-HTP)." (Sept. 5, 2012) http://www.umm.edu/altmed/articles/5-hydroxytryptophan-000283.htm
- WebMD. "Diet for Stress Management Slideshow: Stress-Reducing Foods." Last reviewed April 23, 2012. (Sept. 5, 2012) http://www.webmd.com/diet/ss/slideshow-diet-for-stress-management
- WebMD. "Foods that Fight Winter Depression." (Sept. 5, 2012) http://www.webmd.com/depression/features/foods-that-fight-winter-depression
- WHFoods. "Omega-3 fatty acids." (Sept. 5, 2012) http://whfoods.org/genpage.php?tname=nutrient&dbid=84
- WHFoods. "Vitamin D." (Sept. 5, 2012) http://whfoods.org/genpage.php?tname=nutrient&dbid=110