Seasonal affective disorder (SAD) is a type of depression that occurs during a certain time of year—most commonly during the long, dark winter months. Although its origin is not absolutely clear, SAD is commonly linked to a lack of sunlight.
Did you know?
SAD can also make the summer months the most hated season for some people. For a small but significant minority of people, the condition, referred to as summer SAD, can cause symptoms like loss of appetite, sleep problems, weight loss, and anxiety.
While the cause of SAD isn’t currently known, research indicates that two neurotransmitters, serotonin and melatonin, may play a role in the disorder’s onset.
Serotonin, the “feel good” hormone, helps to regulate our moods. Low levels of light—as we experience during seasons with short days and long nights—are associated with lower levels of serotonin in our bodies. As serotonin levels lower, so does our mood.
On the other hand, low light levels are linked to an increase in melatonin, the hormone that saps our energy and helps us fall asleep at night. Those with SAD may produce more melatonin at night and into the early morning, leaving them feeling lethargic through the day.
Though millions are affected by SAD each year, research shows that it occurs more often in women than in men. Additionally, SAD is more common in people living farther from the equator, where there are fewer hours of daylight in the winter. It’s also known to run in families, who are affected by mental illnesses, such as depression.
SAD may be difficult to differentiate from other forms of depression because of the number of symptoms these forms share. But the common denominator is the timing of symptoms: on a cycle, appearing and then disappearing during specific seasons. For wintertime SAD, the symptoms can include:
- fatigue and lethargy
- social withdrawal
- loss of interest
- difficulty concentrating
- overeating and weight gain
Conversely, summer SAD normally causes difficulty sleeping and decreased appetite, leading to weight loss.
Fortunately, there’s no need to muddle through the offending seasons, as treatment options do exist.
Conventional antidepressants such as selective serotonin reuptake inhibitors (SSRIs) can be effective for some people, but their numerous side effects mean they’re often used only as a last resort.
Shown to be just as effective as antidepressants for managing SAD symptoms with only minimal, if any side effects, light therapy can be taken in two forms: bright light therapy and dawn simulation.
Bright light therapy
As its name implies, this therapy involves exposing a patient to extremely bright lights, normally measuring 10,000 lux, for 30 or more minutes within the first hour of waking up (a sunny day is about 50,000 lux).
Using longer exposure times and gradually brightening lights to imitate a natural sunrise, light exposure with dawn simulation takes place while the patient is sleeping.
While researchers aren’t entirely sure why light therapy works, it is thought to compensate for a lack of sunlight during the colder months. Bright light exposure has also been shown in some studies to increase our levels of serotonin while decreasing our levels of melatonin.
Negative air ions
Negative ions—atoms that have gained an extra electron—have long been recognized for having a positive effect on our moods. Naturally, they’re created by sunlight, moving air, and water. However, they can also be created in devices known as negative ion generators.
Not all ion therapies are equal, though. One study found that, while nearly 50 percent of the people with SAD subjected to high-density ions showed significant improvement, only about 23 percent of those exposed to low-density ions had similar relief.
Diet and exercise
Eating a healthy diet is important in managing SAD symptoms. Balanced meals rich in protein, complex carbohydrates, and healthy fats may help to keep unpredictable blood sugar levels—and the unpredictable moods that may accompany them—at bay.
Exercise, meanwhile, can help relieve stress that may build up as a result of SAD and reduce feelings of fatigue. Furthermore, studies have consistently shown that exercise may significantly improve the moods of those suffering from various forms of depression, including SAD.
St. John’s wort
A thoroughly researched natural antidepressant, St. John’s wort may help ease the symptoms of SAD. It works by affecting the brain’s uptake of serotonin, as well as two other mood-controlling chemicals: dopamine and norepinephrine.
This herb can interact with many medications, so ask your health care practitioner to see if it’s right for you.
Rhodiola, often used to help those with elevated stress, has also been shown to be an effective treatment for mild to moderate depression.
Omega-3 fatty acids
Found in foods such as fish, flax, and nuts, omega-3s anti-inflammatory effects may help relieve depression as well as other mood disorders.
Research shows that low levels of vitamin Dmay increase chances of showing depressive symptoms. While some evidence hints that increased levels of vitamin D may help to manage these symptoms, more research is needed to come to a definite conclusion.
Some B vitamins—B9 (folic acid), B6, and B12—may also play a role in regulating our moods. Research is still evolving on the role of B-vitamin supplementation to help manage SAD and other forms of depression.
See the light!
Lifestyle changes—including getting as much natural sunlight as possible—are important components of managing SAD symptoms. During cold, blustery winter days, how can we get enough sunlight?
Explore outdoor activity options
Find an outdoor activity that you love. Whether it’s walking, skiing, or shoveling snow off the driveway, both the exercise and the increased light may help to manage symptoms.
Just get outside!
Get outside—even on a cloudy day. The amount of light we’re exposed to is higher when we’re outside, even on days when the sky’s gray instead of bright blue. If you don’t have opportunities to get outside, try spending as much time as you can by windows.
This article was originally published in the Holiday 2023 issue of Live Naturally magazine.