With daylight saving time beginning on March 8, we can all expect to lose an hour of sleep and, as a result, have our circadian rhythms disrupted. This can leave you feeling tired and out of it during the day. Plus, while seasonal affective disorder tends to be associated with the fall and winter seasons, some people experience it during the spring and summer, too.
But one technique that can help you adjust to the time change — or manage symptoms of SAD — is light therapy, typically using a light therapy lamp. Here’s what you need to know to use it safely and effectively for an energy boost.
What is seasonal affective disorder?
SAD is a disorder predominant during certain months (most commonly during fall and winter) and may ease with the change of seasons. In rare cases, people may experience SAD during the spring and summer, and symptoms resolve during the fall and winter. Some people experience a combination of symptoms such as lethargy, low mood, lack of interest in things they usually enjoy, weight gain and hypersomnia.
Common SAD treatments include medication, psychotherapy and phototherapy (light therapy).
Seasonal affective disorder symptoms
Seasonal affective disorder will look different depending on how you express it. The common symptoms mentioned in the Diagnostic and Statistical Manual of Mental Disorders, aka DSM-5 — where it’s referred to as a major depressive disorder with seasonal pattern — include the following:
- Feelings of sadness
- Sleeping more than usual
- Feeling tired or unusually fatigued in spite of adequate sleep
- Feelings of worthlessness or guilt
- Craving carbohydrates or otherwise changing one’s typical appetite
- Loss of interest in activities
- Difficulty with thought, decision-making and concentration tasks
- In severe cases, thoughts of suicide or death
Why do some people get SAD?
While there isn’t a known cause for SAD, women are four times as likely as men to experience SAD. A family history increases one’s likelihood of having it, as does having past major depression or bipolar disorder. It correlates with living far north or far south (where winter months receive much less sunlight) and with not getting enough vitamin D, which is produced during sunlight exposure.
What is light therapy?
Because adequate sunlight and vitamin D appear to reduce the prevalence of seasonal affective disorder, various specialty lamps have been created to provide this light. Sun lamps, also known as “happy lamps,” provide light therapy by offering around 10,000 lux (a unit of light) of light with most, if not all, of the UV radiation filtered out.
Light therapy involves sitting or standing in direct light for around 20 to 30 minutes each day. Different colored filters are also considered helpful, in addition to typical white-light lamps.
Types of light therapy
While many SAD lamps offer full-spectrum visible light, which appears white, other people have studied the effect of different colors of light on seasonal affective disorder.
Blue light therapy
Though more research is needed, evidence has shown that the blue wavelength of visible light accounts for much of the benefit derived from bright light therapy for depression and low mood.
Red light therapy
While red light therapy is known to benefit one’s skin, it generally doesn’t show the same research-backed benefits for seasonal affective disorder as blue and green light therapy do. In some studies, red light has been associated with better sleep, so if sleeplessness is part of your SAD symptoms, red light may be a good option.
Green light therapy
A study directly contrasting green-hued light therapy with red light therapy found green to be more effective. However, because sample sizes are often small for these types of studies, it may be helpful to consult your doctor to find the best hue for you.
Benefits of light therapy
Getting more sunlight-like light in your days may be beneficial for your mood. If you have seasonal affective disorder, here are some ways that light therapy can help.
Effective treatment for SAD symptoms
The theory behind light therapy is that vitamin D and sunlight stimulate serotonin production. Serotonin is an important neurotransmitter that affects mood. Getting more light exposure is thought to improve your mood regulation.
Light therapy is linked to short-term relief — meaning that it may be effective at relieving symptoms when they occur, but it won’t prevent you from getting SAD in the long run.
Improves depression symptoms
Individuals who have used light therapy report a lessening of depression symptoms when they take a symptom inventory compared to individuals who receive no intervention or a different light intervention, so much so that it has been used in non-seasonal depression cases as well.
Helps aid sleep
Just as blue light exposure has been shown to energize and, therefore, not be great right before bedtime, red light has been shown to have a more calming, sleep-encouraging impact. If part of your seasonal affective disorder symptoms involves a struggle to fall asleep, using a red light lamp before sleep could help transition from wakefulness.
Potential risks of light therapy
Even though light boxes and light therapy are generally considered safe, it’s best to talk to your health care provider to ensure this is the right option for you and to minimize potential drawbacks. Potential side effects of using a light box include:
- Headaches
- Irritability
- Eye strain
- Nausea
- Induced manic symptoms (if you have bipolar disorder and increase light exposure too fast)
How to use light therapy for seasonal affective disorder
1. Talk with your doctor or mental health professional. They will know if any elements of your unique medical profile require caution with a light therapy lamp.
2. If you are told that light therapy could be a good fit, consider borrowing a lamp first if this option is available to you. If you can find a lamp with multiple color filters, you can use them to evaluate what kind of light therapy works best for you.
3. Begin your light therapy with a white light lamp that emits 10,000 lux and no UV radiation. Put the lamp to your side and at least a foot away from your body, and observe any other instructions in your particular lamp’s operating guidance.
4. Consider a 30-minute session in the morning or spread a few minutes with the lamp throughout your day. Keeping a daily thought journal and evaluating your mood can help you see if and how your light use is helping.
5. If you’re under the care of a psychiatrist or mental health counselor, talk with them about the benefits you’ve received from the light therapy. They may have other suggestions for combining it with other seasonal affective disorder treatments.
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