How to Fight Off Seasonal Depression: Phototherapy, Circadian Health & Clinical Care
Evidence-based strategies and medical treatments for managing Seasonal Affective Disorder (SAD) as daylight hours dwindle in the Midwest.
As autumn transitions to winter across the Chicago area, the rapid shortening of daylight hours brings more than just cooler temperatures. For millions of Americans, the changing seasons can bring on Seasonal Affective Disorder (SAD), a type of depression with a recurrent seasonal pattern that, in most cases, starts in the late fall or early winter and goes away during the spring and summer.
While many individuals notice a mild case of the "winter blues," true seasonal depression is a serious clinical condition that, according to the American Psychiatric Association, affects about 5% of U.S. adults. It can significantly disrupt daily energy, concentration, work performance, and personal relationships. Fortunately, effective treatments are available.
The Science Behind the Winter Shift
Researchers are still determining what causes SAD, but research points to the effects of reduced sunlight on the body's internal clock, which is coordinated by the suprachiasmatic nucleus (SCN) in the hypothalamus:
Studies indicate that people with SAD, especially winter-pattern SAD, have reduced levels of serotonin, a brain chemical that helps regulate mood. Research suggests sunlight affects molecules that help maintain normal serotonin levels, so shorter days may contribute to lower serotonin in winter.
Melatonin is a hormone that helps regulate the sleep-wake cycle. People with winter-pattern SAD may produce too much melatonin, which can increase sleepiness and lead to oversleeping. Winter-pattern SAD is also commonly associated with craving carbohydrates and weight gain.
Bright Light Therapy (BLT) & Dawn Simulation Protocols
Since the 1980s, light therapy has been a mainstay for treating winter-pattern SAD. Talk with your provider before starting, especially if you have an eye condition or take medications that increase sensitivity to light.
The 10,000 Lux Light Box Protocol
- Intensity: Use a specialized clinical light box that emits 10,000 lux of white, UV-filtered light (regular household lamps are insufficient).
- Timing: Light therapy is usually done first thing in the morning; evening sessions may disrupt sleep.
- Duration: Follow the device's distance instructions and use it for the time your provider recommends (commonly about 20 to 45 minutes a day) while reading, eating breakfast, or checking email.
- Eye Positioning: Keep your eyes open, but do not stare directly into the light; the light should reach your eyes indirectly.
Dawn Simulators
A dawn simulation alarm clock gradually increases the light in your bedroom before your alarm sounds, mimicking a natural sunrise. Some studies suggest dawn simulation may help with morning waking and seasonal symptoms, though the evidence is more limited than for bright light therapy.
Proactive Autumn Preparation & Clinical Management
If you have had seasonal depression before, planning ahead can help:
- Begin Light Therapy Early: Because symptoms tend to return in late fall, some people begin light therapy in early fall to help prevent symptoms; ask your provider whether this makes sense for you.
- Maximize Natural Daylight: Spend time outside during midday hours, even on overcast winter days, when outdoor light is still much brighter than typical indoor lighting.
- Prescription Medical Management: When light therapy and lifestyle changes do not provide enough relief, our psychiatric providers can evaluate whether antidepressant treatment is appropriate. Extended-release bupropion is FDA-approved to help prevent seasonal depressive episodes, and SSRIs are sometimes used to treat symptoms.
- Differential Diagnosis: A comprehensive psychiatric evaluation helps distinguish seasonal depression from bipolar disorder (SAD is more common in people with bipolar disorder, especially bipolar II), because the diagnosis affects which treatments are appropriate.