Light therapy is a science-based treatment that is gaining increasing recognition for addressing psychological and sleep-related disorders. In this article, we dive deep into the workings, applications and scientific basis of light therapy.
What is the impact of light therapy on sleep?
Light therapy affects our biological clock through exposure to specially designed light sources. This light, usually bright white-blue with an intensity of 9,000-10,000 lux, reduces the production of melatonin (the hormone that causes sleepiness) and stimulates serotonin (the happiness hormone). This process helps reset sleep-wake rhythms, which can lead to improvements in mood, energy and sleep quality.
The therapy works through connections between the retina in the eye and specific brain areas. Ordinary indoor lighting is not sufficient for this purpose: a standard table lamp offers only 300 lux, while office lighting is around 500 lux according to European standards (NBN-EN 12464-1). Therefore, specialized lamps or light glasses are used to achieve the desired therapeutic effect.
When is light therapy most effective?
One of the most well-known uses of light therapy is for seasonal affective disorder (SAD for short), also known as winter depression.
In northern Europe, about 30% of the population is affected by SAD annually. In Belgium and the Netherlands it is 8%, while 8% experience milder symptoms. This disorder is characterized by depressive symptoms such as fatigue, gloom and increased need for sleep during the dark winter months.
The cause lies in a lack of natural daylight, leading to a hormonal imbalance: less serotonin and more melatonin. Light therapy helps restore this balance and is considered a standard treatment for SAD. Many users report an improvement in their mood and energy levels within just a few days.
As you live closer to the equator, the chance of winter depression decreases. The closer to the poles, the greater the chance of SAD.
Does light therapy help with other conditions?
Although light therapy is best known as a treatment for winter depression, research has shown that it can be effective for other conditions as well:
- Non-seasonal depression: Although the evidence here is more limited, light therapy is sometimes considered when medication is ineffective or has unwanted side effects.
- Bipolar disorder: Studies show that light therapy can help bipolar depression without increasing the risk of (hypo)mania. It is considered a third-line treatment option.
- Sleep disorders: Light therapy can help with problems such as shift work disorder, jet lag and delayed sleep phase syndrome. For night workers, smart light glasses are used to support circadian rhythms.
- ADHD-related sleep problems: In children with ADHD, sleep problems are often exacerbated by medication or behavioral symptoms. Research suggests that light therapy may help improve sleep quality and possibly even reduce ADHD symptoms.
- Dermatological disorders: Dermatologists have successfully applied light therapy as a treatment method for a variety of skin conditions such as psoriasis, eczema, vitiligo and uremic itchingfor several decades.
How do you use light glasses?
We would like to give you some practical tips for using light therapy:
- Use light glasses or lamp for 30 minutes immediately after waking up to activate your biological clock.
- For evening activities, additional use around 4 p.m. may be helpful.
- Combine morning light with evening use of orange glasses that block blue light to stimulate melatonin production in the evening.
In clinical settings, a structured protocol is usually followed, for example, 45 minutes of light therapy daily for one week, often in a psychiatric outpatient clinic.
Is light therapy healthy for everyone?
Although light therapy is promising when applied correctly, there are some limitations:
- Evidence for non-seasonal depression and ADHD-related applications is still developing.
- Some conditions continue to require additional research to further substantiate effectiveness.
Still, light therapy certainly offers a safe option for many people. The number of side effects reported are rather low. As more studies are conducted, new uses may be discovered and protocols further refined.
Conclusion – How does light therapy work?
Light therapy is a powerful method for addressing mood disorders and sleep problems by recalibrating the biological clock. Whether you struggle with winter depression, sleep problems or other related conditions, this therapy offers a science-based solution that you can easily incorporate into your daily routine. With the right guidance, light therapy can help improve mood, energy and healthier sleep habits.
