People today spend 90% of their time indoors. This means we are exposed to less light during the day and increasingly use nighttime light. According to the Institute of Mental Health, lack of sunlight is the primary cause of seasonal affective disorder-associated symptoms in winter. When our relationship with the sun changes, it affects our biology. The body's biological clock (24-hour fluctuations in biology and behavior) cannot adapt to the changes in the shortening of daylight, which results in circadian rhythm and endocrine disorders. Light directly affects the secretion of serotonin and melatonin in the human body, and these two substances are closely related to poor emotional and mental states.
Although SAD affects people of all ages, women aged 18 to 30 are more likely to experience winter depression than men.
Patients with SAD have typical symptoms of:
- Feeling helpless, sad
- Suicidal thoughts
- Drowsiness, oversleeping
- Difficult to concentrate
- Irritability
- Poor cognition
- reduced social activities
- Weight gain
Conditions associated with SAD are not something to be taken lightly. In many cases, people don't want to talk about their depression, which can exacerbate their condition.
How Does Red Light Therapy Help Combat Seasonal Depression (Winter Blues)?
Treatment of seasonal depression usually uses a combination of medications, psychotherapy, and light therapy. About one-third of people with major depressive disorder do not respond well to existing anti-depressants. Fortunately, without anti-depressants, SAD is possible to treat. Phototherapy is unanimously regarded as the best treatment option to relieve seasonal depression symptoms. Light is the most essential energy source, consisting of the complete electromagnetic spectrum fundamental to human survival on Earth.
Red Light therapy or photobiomodulation is a non-pharmacological, safe technique based on phototherapy principles that utilize visible lights. It uses clinically proven spectral ranges most effective in these treatments: 630-660 nm (visible red light) and 850-940 nm (near-infrared). Nearly 90% of the information obtained by human beings from the outside world needs to be collected and transmitted through the eyes. Because it is visible and perceptible, visible light can have a vital impact on human physical and mental health from the three dimensions of vision, physiology, and psychology. 
Since the 1980s, red light boxes have been used to treat seasonal affective disorder (SAD). Research suggests that red light therapy influences neurotransmitters' production and regulation to improve mental health. We know that exposure to certain rays is dangerous. But red and near-infrared lights from the visible spectrum with unique wavelengths and frequencies have a soothing effect on mental and physical well-being.
Red Light Therapy Regulates the Circadian Rhythm
Many human behaviors and physiological phenomena, such as sleep, blood pressure, heart rate, body temperature, etc., have a circadian cycle, and this physiological phenomenon that repeats every 24 hours is called circadian rhythm.
The disturbance of the biological clock is believed to be a root issue of seasonal affective disorder and causes various symptoms, from mood disorders to lack of energy. Red light exposure not only influences your body clock and sleep but also positively affects your mood.
- Serotonin and dopamine areneurotransmitters that help to control mood. Reduced exposure to light in winter causes imbalances of these neurotransmitter productions. SAD may be associated with low extracellular levels of dopamine. Dopamine makes people happier, smarter, focused, and more social. One study found that transcranial photobiomodulation for depression treatment increases serotonin synthesis in the brain and relieves anxiety. Norman Doidge, a well-known psychiatrist and researcher from the University of Toronto, discusses the red light therapy dopamine production stimulating on brain cells in his book, The Brain's Way of Healing. Red light therapy exerts anti-depressant effects and boosts mental performance.
- Melatonin secretion,which controls the sleep-wake cycle in response to darkness. Melatonin secreted by the pineal gland is physiologically suppressed by light. As the days become shorter in winter, melatonin hormone secretion increases, which causes drowsiness and fatigue in SAD patients, often accompanied by a delay in circadian rhythms. Unlike other types of light, red light therapy, with its longer wavelength of spectrum, is a powerful sleep promoter. Research studies showed that red light in the wavelength range of 600-900 nm inhibits melatonin production, restores the body's internal clock, and fixes depression.
Another study showed that red light significantly enhanced the intensity of brain β wave activity, reduced subjective drowsiness, and induced more positive emotional experiences.[4]
- Increased cortisol(stress hormone) secretion intensifies depression and other SAD symptoms. Red light therapy stimulates the body's metabolism, promotes relaxation, and lowers cortisol levels. Regulation of cortisol levels boosts low mood, relieves fatigue, and suppresses hunger in response to changes in appetite. A small pilot study enrolled ten patients with a history of major depression and anxiety and subjected them to red/near-infrared light on their foreheads for four weeks. At the end of 4 weeks, 10 out of 6 patients experienced relief of depressive symptoms, and 10 out of 7 patients had reduced anxiety symptoms. [5] In addition, by accelerating the amount of energy flowing to the brain, red and near-infrared light improves cognitive performance.
Final Thoughts
Winter, which seems to be an ordinary season, has invisibly brought unexpected damage to many people's mental health. Remember to add vibrant red light into life when you can't stand the cold and nights Due to its effectiveness, convenience, and safety advantages, the Bestqool red light therapy device can be a valuable addition to your life. It will mimic the sunlight effect and prompt your brain to secrete more anti-depressing chemicals to elevate your mood.
References & Citations
[1] National Institute of Mental Health. "NIMH» Seasonal Affective Disorder (SAD)." Institute of Mental Health, 2020.
[2] Nusbaumr-Streit, B., Forners, C. A., Morgan, L. C., Van Nord, M. G., Gayns, B. N., Greenblat, A., Wiplinger, J., Lux, L. J., Winkler, D., & Gartlehnr, G. (2019). Light therapy for preventing (SAD). The Cochrane data of systematic reviews, 3(3), CD011269.
[3] Eshghi, E., Sadigh-Eteghd, S., Mohades, G., & Rasta, S. H. (2019). Transcranial photobiomodulation (PBM) prevent anxiety depression via changing serotonin and NO levels in brain of depression model: A study of three different doses of 810 nm laser. Lasers in surg and med, 51(7), 634–642.
[4] Figuero, M. G., Sahin, L., Rohan, C., Kalshr, M., Pltnick, B., & Rea, M. S. (2019). Effects of red light on sleep inertia. Nature & Sci of sleep, 11, 45–57.
[5] Schifer, F., Johnston, A. L., Ravichandrn, C., Polcari, A., Teicher, H., Web, R. H., & Hamblin, M. R. (2009). Psychological benefits after treating with red/near infrared light to the forehead: pilot study of 10 patients with major depression and anxiety. Behavioral and brain functions : BBF, 5, 46.
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