Many people consider fall and winter their favorite time of the year, but did you know that at least 20 percent of Americans actually become depressed during this period? This condition is known as seasonal depression or, more commonly, seasonal affective disorder (SAD).
Basic Facts About Seasonal Depression: Who Is at Risk?
Seasonal affective disorder (SAD) is a subtype of bipolar depression or clinical depression that is intricately linked to the changing seasons. It typically occurs at the same time every year — starting during fall and then progressing into the winter months.1
However, what sets SAD apart from regular depression is that those who are affected go into full remission during springtime and summertime. Seasonal depression may also occur in the summer or spring, although this is less common. SAD more commonly affects women. Four in 5 people with this ailment are actually female. It also usually occurs among adults ages 20 to 30 years old, although symptoms can appear earlier.2
Another potential risk factor of SAD is your location. It’s said that if you live far from the equator, whether up north or down south, there’s a high chance that you will be affected by this condition. According to Mayo Clinic, “This may be due to decreased sunlight during the winter and longer days during the summer months.”3
Causes and Symptoms of Seasonal Affective Disorder
The onset of SAD has been linked not only to a person’s biological clock (circadian rhythm), which is disrupted when there is a reduced level of sunlight, but also because of two hormones: serotonin and melatonin.
The levels of serotonin, the neurotransmitter responsible for a person’s mood, drop because of the reduced amount of sunlight, which then triggers sadness and depression. Meanwhile, production of melatonin, the sleep-related hormone, peaks because of the darkness brought on by shorter days, affecting mood and sleep patterns.4,5
Seasonal depression can be diagnosed if a person has two consecutive incidences of depression that manifested and ended at the same time every year, with symptoms disappearing the rest of the year. These can include:
Hopelessness and sadness
Appetite changes (many people crave sweet or starchy foods)
Having suicidal thoughts
Low energy levels
A heavy feeling in the legs or arms
Increased sensitivity to social rejection
Avoiding social situations
The Best Solution for SAD: Light Therapy
One study found that full-spectrum light therapy may be particularly effective in the treatment of seasonal depression and may even work for clinical depression. In fact, it may be better than antidepressants for alleviating this disorder.6 This is not surprising, as bright light, such as from sunlight or light therapy lamps, actually helps reset your circadian rhythm.
Blue light is found to be particularly beneficial for boosting your mood, and works better than red or green light. One 2010 study found that blue light may be a key factor in your brain's ability to process emotions, and that spending more time in blue-enriched light may help prevent and/or treat seasonal depression and clinical depression.7
Other Strategies to Avoid Seasonal Depression
If light therapy is not an option for treating SAD, these simple lifestyle strategies may prove to be effective:
• Check for a vitamin D deficiency and treat it if you’re found deficient. Being deficient in this nutrient has long been associated with SAD8 and chronic depression. Ideally, going out in the sun is the best way to optimize your vitamin D levels, but in dark winter months, taking a vitamin D3 supplement is an ideal alternative. Remember to take vitamin K2 and magnesium with it, along with some form of healthy fat to optimize the absorption.
• Go to sleep early. Maintaining a regular sleep schedule and following high-quality sleep tips can go a long way in alleviating depression. One study found that 87 percent of depressed individuals who resolved their insomnia experienced significant improvements. Their symptoms disappeared after eight weeks9
• Avoid processed foods. What you eat can have a significant impact on your mood and overall health, so make sure you choose wholesome, high-quality organic foods prepared at home. Eliminate sugar and grains, which can mess with your insulin and leptin levels, from your diet as well.
• Get enough exercise. Exercise improves your endorphin (feel-good hormone) levels, as well as normalizes your leptin and insulin signaling.
• Increase your omega-3 intake. Your brain is actually made up of 60 percent DHA omega-3 fat. A 2009 study showed that people who have low blood levels of omega-3s are more likely to become depressed than those with higher omega-3 levels.10