Does Light Therapy Work? - Infographic
Expert Findings Answering "do SAD Lamps work?"
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While bright light therapy has proven itself as an effective, safe, and holistic treatment for various health conditions, it does sound too good to be true. Before entering the world of light therapy, I was a skeptic myself. I was even gifted a few sunlight lamps that I never really gave a chance. However, after doing countless hours of research and using one daily, I now see the power light box therapy holds.
If you've found yourself asking, "do light therapy lamps work," "do sun lamps work," or "does light therapy really work for depression" then this article is for you. Below, we highlight expert studies and findings on light therapy for Seasonal Affective Disorder, various sleep disorders, non-seasonal depression, ADHD, and more. All of the results have been illustrated to make them easy to read.
If you've been finding yourself asking, "does light therapy really work," then continue reading.
What is Light Therapy?
Bright light therapy is a holistic treatment that involves using high-powered therapy lights that mimic sunlight. These phototherapy lights typically deliver 10,000 LUX light to trigger biological effects in the body. When exposed to these bright light therapy lamps, the body produces serotonin which later converts to melatonin. Serotonin plays a vital role in the body by regulating moods, energy levels, digestion, and more. When it gets dark out, serotonin converts to melatonin which regulates the body's sleep-wake cycle (circadian rhythm).
Many health conditions such as seasonal affective disorder, circadian rhythm disorder, ADHD, and anxiety result from hormonal imbalances in the body. And because sunlight therapy lamps are a source of those essential hormones, they're commonly used as a treatment method.
Seasonal Affective Disorder
Do light boxes work for SAD?
Seasonal affective disorder, also known as seasonal depression, is a type of depression that coincides with each year. This mental health condition is usually accompanied by a surge of sadness, low energy, and thoughts of hopelessness. Seasonal depression lamps work to relieve SAD symptoms by mimicking sunlight to boost serotonin and melatonin levels.
A study from 14 research centers with 332 patients over five years found:
- 2,500 LUX light therapy for a minimum of two hours daily for one week resulted in significantly more remissions compared to dim light
- Morning light therapy is most effective. When looking at efficiency, the study compared how well each time resulted in a Hamilton Depression Rating Scale (HAM-D) of 50% to a level under eight:
- Morning: 53%
- Midday: 32%
- Evening: 38%
A study involving 177 adults with diagnosed SAD compared six weeks of cognitive-behavioral therapy (CBT-SAD) to six weeks of daily 30 minute 10,000 LUX light therapy. The study found comparable results with the following remission rates:
Hamilton Rating Scale for Depression-SAD Version (SIGH-SAD):
Beck Depression Inventory-Second Edition (BDI-II):
The study concluded that both are comparable for treating acute episodes of SAD and may be considered as treatment options.
61% of the 96 patients during a four-week study experienced a 50%+ remission of SAD symptoms after exposure to a 6000 LUX seasonal affective disorder lamp for 1.5 hours daily.
Two meta-analyses of eight studies involving 703 participants both concluded that light therapy showed efficacy in treating SAD when compared to a control condition.
A study involving 15 patients with SAD found an immediate improvement in mood with the first session of seasonal affective disorder light therapy with exposure as little as 20 minutes. The study found those who used a sun lamp for seasonal depression for 40 minutes experienced even better moods than 20 minutes. Depression scores did not differ from 60 minutes compared to 40.
Ninety-six patients with SAD were administered 6000 LUX light therapy for 1.5 hours/day for 1-3 times per week for four weeks. The seasonal depression light therapy lamps produced complete remissions while having a specific antidepressant effect over the placebo effect in three weeks.
An analysis of 17 studies on sun lamps for SAD found:
- A high response rate in about 67% of patients with milder SAD and 40% in severe patients
- Early morning treatment offers greater chances of remission
- Lower SAD light therapy lamp intensities appear to be effective but need longer exposure times: 2500 LUX for 2 hours/day, 5000 LUX for 1 hour/day
- Light therapy lights for SAD reduced the risk of reoccurrence by 36%
Common sleep disorders such as circadian rhythm disorder and insomnia are typically a result of an irregular sleep-wake cycle. Light therapy for sleep helps relieve sleep disorders by resetting the sleep-wake cycle, so the body produces the needed melatonin at the right time of day (in the evening). When we have adequate melatonin levels, our bodies are better able to fall asleep at night.
A meta-analysis involving 53 studies and 1,154 participants found light therapy to be effective for general sleep problems in addition to circadian rhythm sleep disorders, insomnia, and alzheimer's/dementia-related sleep difficulties.
A review found that morning light therapy advances the circadian rhythm of those with sleep-onset insomnia. At the same time, evening light therapy delays the circadian rhythm and sleep/wake pattern of those with morning awakening insomnia.
Nine patients with morning awakening insomnia were given evening 2500 LUX light therapy between 8 PM and 12 AM for two consecutive evenings and showed an average increased sleep time greater than one hour.
Sixteen patients aged 62 to 81 were treated with either timed bright white or red dim light for 12 consecutive days. Exposure to the bright white light yielded an improved sleep efficiency from 77.5% to 90% and increased sleep time in the form of stage 2 sleep, REM sleep, and slow-wave sleep. Waking time within sleep was also reduced by one hour.
Twenty-four adults with early-morning awakening insomnia were assigned either 2,500 LUX white light or a control of dim red light for two evenings. While the control group showed no significant changes, the light therapy group had a significant two-hour phase delay of circadian temperature and melatonin rhythm. A four-week follow-up period showed the light therapy group had a more substantial reduction of time awake after sleep onset, had a trend of waking later, and an increase in total sleep time.
A study of 20 patients with delayed sleep phase syndrome (DSPS) found two hours of bright light exposure in the morning combined with evening light restriction to successfully phase advanced circadian rhythms of core body temperature and multiple sleep latencies.
Patients with sleep onset insomnia were treated with 2500 LUX light therapy for one week and experienced:
- A 1 hour and 21-minute phase advance of melatonin onset
- A decrease of sleep onset latency
- A significant advance of sleep onset time
- A significant increase of total sleep time by 51 minutes
- Decrease in insomnia severity
- Less presleep anxiety
- Improved overall daytime functioning and less daytime fatigue
Do SAD Lamps Work for Depression?
Those with non-seasonal depression typically experience similar symptoms as those with seasonal affective disorder. The main difference is non-seasonal depression does not correlate with the time of year. Instead, it is a condition that might be prevalent all year long. Light therapy for depression helps reduce symptoms by boosting serotonin levels to make emotions more manageable and improve sleep.
A systematic review involving 15 reports found bright light therapy to be as effective, if not more, in treating non-seasonal depression compared to antidepressants.
A meta-analysis of nine trials found using a light box for depression to reduce depressive symptoms by 62%.
One study found using a light lamp for depression in combination with antidepressants to achieve the target HDRS score 76% of the time compared to 44% of patients treated with antidepressants alone.
An eight-week study with 122 patients comparing light therapy plus fluoxetine vs. fluoxetine alone found the combination to reduce MADRS scores by 16.9 compared to 8.8 with fluoxetine alone.
A study on the effects of light therapy on 27 pregnant women with antepartum depression found 7,000 LUX morning light treatment for five weeks at one hour per day to be effective in 81% of patients compared to a success rate of 41% of those given a placebo dim light. Additionally, remission was achieved in 69% of light therapy patients compared to just 36% of placebo patients.
An analysis of 40 studies of the effects of therapy lamps for depression found:
- Depression light therapy lamps are an effective adjunct with antidepressants and improve the effectiveness in the first week of treatment
- Light therapy in unison with SSRIs leads to a faster and better remission by reducing 30% of symptoms within the first week compared to SSRIs alone
- 1200 to 10000 LUX light box therapy through six weeks for 30-60 minutes per day is an effective treatment in reducing elderly symptoms of depression
Sleep disturbances are a significant side effect of ADHD, making light therapy an option for treatment. Because sleep is critical to mental health, those with ADHD experience worsened symptoms as a result.
A study of the effects of light therapy on 29 adults with ADHD found the treatment to decrease ADHD symptom scores by 15%, increase mood scores by 52% and improve their circadian rhythm scores by 11%. The patients were given light therapy for three weeks from November 2003 to February 2004.
Patients with ADHD underwent two weeks of 30 minutes morning treatment with a 10 000 LUX light therapy lamp and minimized overhead light after 4 PM. Participants experienced advanced Dim Light Melatonin Onset (DLMO) by 31 minutes and mid-sleep time by 57 minutes. These increased phase advances were directly correlated with decreased ADHD-RS total scores and Hyperactive-Impulsive sub-scores.
Twenty-nine adults aged 18 to 60 were administered three weeks of 30 minute 10000 LUX full-spectrum light therapy each morning before 8 AM during the fall/winter. After those three weeks, participants experienced significant improvements in mood, core ADHD symptoms, and a circadian shift towards morningness as individuals.
Dementia is a condition in which cognitive decline occurs. Those with dementia show degradation of core memories and may struggle with everyday tasks. And because they lapse in memory, sleep disturbances occur. This shows in the form of sleeping too much or too little and at irregular periods.
A study of 10 patients who underwent 1500-2000 LUX light therapy for 2 hours from 7 PM to 9 PM for one week resulted in improved sleep-wake patterns, decreased nighttime activity and increased sleep-wakefulness.
Six patients were administered 4000 LUX light therapy in the late-early morning. Three of the six patients experienced more sleep during lights-out periods and more wakefulness during the daytime. The other three participants experienced advanced sleep onset time. All six subjects experienced reduced abnormal behavior episodes around lights-out periods.
Eight patients administered one hour of daily light therapy for four weeks experienced significant improvements in nocturnal sleep from a mean of 6.4 hours/night to 8.1 hours/night.
Eleven nursing home patients were treated with morning light therapy for two weeks, from 8 AM to 11 AM. They experienced a decrease in the nocturnal wake by nearly two hours and an increased sleep efficiency from 73% to 86%.
Eleven patients with dementia were treated with morning light therapy for two hours/day for two weeks. The participant's daytime sleep decreased significantly between their rising time and 3 PM.
Shift Work Adjustment and Jet Lag
Having a consistent sleep schedule is vital to being healthy. However, careers such as nursing or those with heavy travel typically involve an ever-changing sleep schedule. Light therapy offers a solution when used to shift one's sleep-wake cycle to minimize the side effects.
A study exposed 28 participants to three days of morning light therapy and found the treatment to shift their circadian rhythms by 2.1 hours.
Forty-six nurses undergoing rotating shifts were exposed to 7000-1000 LUX bright light therapy for 30 minutes per day for 10 days. They found a reduction in insomnia, anxiety, and depression severity.
Anxiety is often associated with symptoms of fear, dread, and uneasiness. These feelings often affect sleep. Because light therapy boosts melatonin, it offers a solution to reducing anxiety symptoms and the sleep disturbances accompanied by it.
Fifty-eight patients with focal epilepsy given a daily SAD light for anxiety experienced reduced anxiety and depression scores after 12 weeks.
Seventy-nine participants were exposed to three hours of 3000 LUX light therapy for three consecutive days. Anxiety scores were recorded five minutes before treatment and 20 minutes after. The study found a decrease in the average score of anxiety.
These findings on light therapy lamp benefits offer an insight into whether lightboxes are effective in addition to the science behind happy light treatment. If you find yourself struggling with the listed above mental disorders, consult your doctor about light therapy as a potential treatment. We also have a variety of light therapy resources for further information.
About the Author
Brandon Landgraf is the Digital Marketing Manager for Carex Health Brands. He finds passion and fulfillment in creating content that enhances, improves, and enlivens others' quality of life. All of his written work is formulated to not only offer essential advice and tips but back it with proven studies and experts. His mission is to connect with readers and provide steps to make their lives better.
You can connect with him on LinkedIn here.
About Carex Health Brands
Carex is your one-stop shop for home medical equipment and for products that assist caregivers with providing the best possible support and care for their loved ones. Carex Health Brands has been the branded leader in in-home, self-care medical products for over 35 years. Our goal is to improve the lives of our customers by bring them quality products that bring dignity back to their lives. With our three nationally distributed brands, Carex Health Brands serves national, regional and independent food, drug and mass retailers along with wholesalers, distributors and medical dealers.
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