If you have seasonal affective disorder, also known as SAD, then the long, dark fall and winter months may trigger symptoms of depression. Though not as common, you can also experience SAD during the summer months. Your doctor may recommend light therapy for this type of depression.
Regular indoor lights aren’t bright enough to boost your mood. Light therapy for SAD involves using a light box. Here’s what you should know about how a light box for depression works to treat SAD.
Does Light Therapy Help with Seasonal Depression?
Light therapy is one of the main treatments for seasonal depression. It’s effective in improving symptoms and mood changes caused by SAD. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) identifies SAD as a major depressive disorder with seasonal pattern.
Light therapy for depression tries to replace the natural light that you miss during the winter months that can trigger your depression. Light therapy may work best when used with a special type of cognitive behavioral therapy or talk therapy. Known as CBT-SAD, it helps people cope and replace negative thoughts the winter season causes with more positive thoughts.
Both CBT-SAD and light therapy are equally effective in improving SAD symptoms. But a long-term study following SAD patients for two winters found the positive effects of CBT-SAD seemed to last longer over time. So combining the two may help more.
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What Is a Light Box?
A light box for depression is a device that mimics natural light. Light therapy uses a 10,000 lux fluorescent light box, which is about 20 times brighter than ordinary indoor light. Lux units measure light intensity.
How To Use a Light Box to Treat Depression
To use a light box for SAD, you need to sit in front of it daily at regular time intervals. How long you need to sit in front of the light box can vary. These tips can help:
- Use the light box first thing in the morning, before you head out to work or school.
- Use it from fall to spring.
- Start your light box therapy in October. This is what the National Alliance on Mental Illness recommends.
- Use the light box for at least 20 minutes per day. The National Institute of Mental Health recommends using it for 30 to 45 minutes per day.
- Place it 16 to 24 inches from your face.
- Keep your eyes open, but don’t look directly at the light. Use the time to eat breakfast or read a book or emails.
- Give it time to work. Most people who use light therapy for depression see their symptoms improve within one or two weeks of beginning treatment. That’s according to the American Psychiatric Association.
How To Choose the Right Light Box
Unlike medications for depression, light boxes aren’t approved or regulated by the Food and Drug Administration to treat SAD. But they are safe and effective to use.
Their design’s purpose is to mimic natural light. They also filter out potentially damaging ultraviolet (UV) light.
Light boxes also go by light therapy boxes, bright light therapy boxes, and phototherapy boxes. Follow these tips to choose one:
- Talk to your doctor or therapist first to find out if using a light box for SAD makes sense for you.
- Ask your doctor or therapist for recommendations. Based on their experience, they may prefer one brand over another.
- Choose a light box that delivers 10,000 lux of fluorescent light, the amount found most effective.
- Avoid light boxes that have UV light, which can damage your eyes.
- Choose one labeled to treat SAD. Some light boxes treat skin disorders using UV light. These don’t work for seasonal depression and can harm your eyes.
Who Should Avoid Light Therapy Boxes?
People who should exercise caution when using light therapy boxes include:
- Those with pre-existing eye diseases, including cataracts or glaucoma.
- Those taking medications that increase sensitivity to sunlight.
- Those with diabetes, which already increases your risk of eye damage. Light therapy can further damage your retina.
- Those with bipolar disorder. Light therapy can trigger hypomania or mania.
You may need to use light therapy under medical supervision or use treatments for SAD.
Seasonal Affective Disorder. National Institute for Mental Health. Link.
Major Depressive Disorder with a Seasonal Pattern. National Alliance on Mental Illness. Link.
Seasonal Affective Disorder. American Psychiatric Association. Link.
Seasonal Affective Disorder: Bring on the Light. Harvard Health Publishing. Link.
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