Do light therapy lamps actually work?

Key Takeaways

• Bright light therapy is considered a first-line treatment for seasonal affective disorder.
• Light therapy lamps might come in handy during the months when daylight hours are shorter.
• When choosing a light therapy lamp, try to look for a UVB-free white light that has 10,000 lux intensity and is wide enough to cover your face.

After a long hot summer, you might be excited to enjoy a reprieve from intense temperatures. But with each day that passes, daylight hours get shorter, and soon enough daylight saving time will follow.

When the day is short, your circadian rhythm responsible for regulating alertness, sleepiness, appetite, and body temperature, can become desynchronized and increase the risk of mental and physical health problems.1

Some people might start experiencing symptoms of seasonal affective disorder (SAD) as early as the autumn.

“From the height of the summer to, say, Labor Day, which is early September, you lose an hour of morning light,” said Norman Rosenthal, MD, a clinical professor of psychiatry at Georgetown University School of Medicine who wrote the book “Defeating Sad.”

Light exposure can stimulate the production of serotonin, a neurotransmitter responsible for mood regulation, and help stabilize the circadian rhythm.2 

During colder months, light therapy lamps can come in handy. They’re supposed to help make up for the loss of light exposure and ease symptoms of SAD. But are they effective?

How Light Therapy Works

SAD is defined as having recurrent episodes of major depression in at least two consecutive years where the symptoms occur at specific times with no non-seasonal episodes. These episodes might begin and end around the same time, for example, from November to March.

Light therapy, also known as bright light therapy or phototherapy, uses specific wavelengths of light to mimic natural light and send signals to your brain’s emotional center to produce serotonin. It also helps increase alertness and regulate your circadian rhythm.

A 1998 placebo-controlled trial found that it took at least three weeks for bright light therapy to work effectively as an antidepressant for SAD.3

Another trial in 2016 found that bright light therapy, whether used alone or in combination with the antidepressant fluoxetine, was effective and well-tolerated for adults with non-seasonal depression.4

Although SAD can occur during the summer, it’s less common.5 SAD is typically mitigated by natural light. Places closer to the equator have less incidence of SAD as they have more exposure to light, Rosenthal said.

Starting light therapy earlier in the cold seasons also makes it easier to keep symptoms from progressing as daylight hours get shorter, according to Rosenthal.

Light therapy is a popular non-invasive treatment option for other mental health conditions too, according to Harold Hong, MD, a board-certified psychiatrist and medical director of New Waters Recovery in North Carolina.

It’s been used to treat anorexia and bulimia nervosa, as well as in conditions involving sleep-wake disruption, such as attention deficit hyperactivity disorder (ADHD), borderline personality disorder, schizophrenia, and neurodegenerative diseases.2

Hong said light therapy has also shown promising results in treating certain skin conditions like psoriasis and eczema.

What to Look for in a Light Therapy Lamp

Light therapy lamps can come in a spectrum of blue and white light. However, there’s far more evidence to prove the efficacy and safety of white light, and it’s the most “natural” environment to sit in, according to Rosenthal.

“There’s no evidence [blue light] has any advantage over white light, so I think it’s a marketing ploy,” Rosenthal said. “Some people like different things.”

In terms of LED bulbs, the recommended intensity for treating SAD and other mental health conditions is 10,000 lux.

Hong said to avoid lights with UVB components as prolonged exposure to UVB rays can damage the skin, much like being out under the sun without sunscreen.

It’s also important to consider the space you’ll be using the lamp in, the lamp’s size, and its angle. Hong said the lamp should be big enough to cover your face at a comfortable angle. If you can, opt for one with adjustable settings like brightness and time duration so you can personalize the lamp to your needs.

For the best results, a light box about the size of one square foot is recommended, Rosenthal added. Also, try to look for a light box that can be easily moved as you go about your morning. Effective placement or having two lamps that you can use together or place in different high-use areas at your home can really make a difference.

How to Maximize the Benefits of a Light Therapy Lamp

The recommended light therapy treatment for SAD is to have 30 minutes of daily exposure to 10,000 lux of light, or one to two hours of exposure to 2,500 lux.5

Think about your routine and use a light therapy lamp in the morning for the boost of energy you’ll need for your day. As the lamp’s effects wear off throughout the day, use it again in the evening, especially if you live in a place where the sun sets earlier, Rosenthal said.

It’s possible to have too much light therapy, but that limit varies from person to person. You can gauge when your “internal light meter” is maxed out if you feel similar to being over-caffeinated or having too much energy, Rosenthal said.

For some people, overexposure to light can lead to a feeling of mania so the duration of light therapy should be limited, he added.

“Light therapy alone is not sufficient,” Rosenthal said. You might be using the light box right and still experience SAD symptoms. In addition to light therapy, exercise, good sleep hygiene, social activities, and cognitive behavioral therapy are all necessary steps to fight off seasonal depression.

What This Means For You

In the colder months, if you have a harder time getting up in the morning, social withdrawal, or feel fatigued more than usual, you might have SAD. Light therapy lamps might help realign your circadian rhythm and stimulate serotonin production. You can also take a morning walk to get more sunlight, exercise regularly, and eat a balanced diet to ease SAD symptoms.