Bright light therapy (phototherapy) is known to have a positive and uplifting effect on mood, especially in the morning hours.
Bright light therapy (phototherapy) can also be used for this purpose. Although observations about this have been known for about a century, it has become a systematic treatment practice in the last 20 years.
Devices used for bright light therapy (phototherapy) are now portable and filter UV light. Research has shown that bright light therapy (phototherapy) improves depressive symptoms by positively affecting mood; has a regulatory effect on circadian rhythm (biological clock); increases the effect of antidepressant medication and regulates sleep quality.
How does bright light therapy (phototherapy) work?
It has been determined that its effectiveness, especially in seasonal depression, may be related to its effect on biological rhythms and that its effect may occur through monoaminergic and melatonergic mechanisms. In major depression, there is a change in the circadian rhythm (biological clock). This is mostly in the form of phase delay. Clinical and epidemiologic studies have shown that the frequency of depression is higher in individuals with phase delay. This phase shift in depression is also responsible for some depressive symptoms.
Melatonin is a neuroendocrine substance that plays an important role in circadian rhythm. Its release increases during night and darkness and decreases during daytime and light. Melatonin is a hormone that can cause depression. Suppression of melatonin release by bright light leads to antidepressant effect.
How is phototherapy applied?
Bright light therapy (phototherapy) is applied at 10,000 lux for half an hour or 2,500 lux for 2 hours, especially in the early morning hours. Practices and studies have shown that treatment efficacy is higher at these doses and durations. The application period is 1 week. During the application process, the person does not look directly at the light source and sits sideways. There should be at least 1 meter distance between the device and the person.
Are there any side effects of phototherapy?
There are no serious side effects. However, it has been reported to cause manic shifts in mood patients when used at high doses and durations.
It has been suggested that bright light therapy (phototherapy) may rarely cause nausea and headache due to increased dose or prolonged duration. No toxic effects on the eyes have been demonstrated. What is important for all these side effects is conscious and controlled use at appropriate doses and durations.
In which cases can it be used?
Bright light therapy (phototherapy) is used in combination with medication for seasonal mood disorders. It was started to be used especially in seasonal depression conditions; later it was found to be effective in non-seasonal depression conditions. In addition, phototherapy can be successfully applied in chronic fatigue syndrome, sleep disorders due to changing working hours or jetlag, and in pregnant women who cannot be treated with medication.
