Dark therapy for bipolar disorders
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- By Koos Meijer
A commonly used strategy in the depressive phase of bipolar disorder is the use of light therapy or bright light therapy. In the manic phases, however, in many situations it is better not to have additional light administered, in this case, dark therapy using blue light blocking glasses can be an effective and drug-free supplement.
Orange glasses as an effective tool during manic-depressive episodes
Bipolar (manic-depressive) disorder is a mood disorder that occurs in approximately 2% of the population. This disorder is characterized by the alternating occurrence of manic and depressive episodes and has a strong recurrent nature. A mania is a period of at least one week, during which you are in an abnormally good mood most of the time, need little sleep and are overflowing with energy or just very irritable. This blog discusses the application of dark therapy using orange, blue light filtering sleep glasses as a practical tool to improve the quality of sleep around manic periods. Please note, it is not a replacement for medication for bipolar disorder. Always discuss the use of dark therapy with your doctor, psychiatrist or psychologist.
Light therapy and dark therapy
A commonly used strategy in the depressive phase of bipolar disorder is the use of light therapy or bright light therapy. Read the protocol for light therapy for bipolar disorders here. In the manic phases, however, in many situations it is better not to have additional light administered, in this case dark therapy can be an effective and drug-free supplement.
Disturbed sleep during the manic period of bipolar disorder
Typical of a manic or hypomanic episode, is the greatly reduced need for sleep. It is common for people to sleep perhaps only a few hours a night and feel fine. It also happens that some people can go through life without sleeping for one or more days. The problem is that the accumulated sleep debt can be accompanied by increased stress and can fuel manic episodes. For these reasons, it is essential to increase sleep duration and improve sleep quality.
Get a better grip on your sleep with dark therapy
Dark therapy works as the opposite of bright light therapy. During dark therapy, special orange sleep goggles are worn that block the blue part of artificial light and daylight. This is because the blue part of light inhibits the release of melatonin in the evening night and early morning. A recent study conducted in 2019, shows that some people are up to 50x more sensitive to blue light in the evening hours than others. Genetic evidence for this has been found. On average, exposure to 30 lux is enough to reduce natural melatonin production by up to 50% and delay it by 70 minutes. This while this light intensity is lower than what is present in the average living room (125 lux) and bathroom (200 lux). By completely filtering out the blue part of the light with the orange glasses, the brain again receives the signal that it is night. How exactly this works I explain in the video below starting at minute 5:50. Dark Therapy.
Blue light photopigment Melanopsin
Dark light therapy works through a photopigment in the eye called melanopsin. This detects mainly the short wavelengths of the light spectrum which is high in blue light. These blue light-sensitive eye cells do not help you see because they are not directly connected to the visual cortex, which is the part of your brain that controls your vision. Instead, the nerve endings are connected to the part of your brain that controls and calibrates your biological clock called the Nucleus Suprachiasmaticus (SCN). Given this receptor is selectively sensitive to short-wavelength light, orange glasses can help calm the brain and biological clock in the evening. The short video below (0:08) tests the blue light filter of the Somnoblue.
Scientific studies: Orange sleep goggles during a manic episode
Contrary to what the term implies, modern dark therapy is not about treating patients in a dark room. Rather, it is about creating virtual darkness in which the patient can function normally. Light without the blue wavelengths, seems to have a negative effect on this patient group. As explained in the videos above, sleep goggles can help with this. After an extensive meta-analysis comprehensive review of the research on chronotherapy, an international group of 27 researchers now recommends so-called "dark therapy" for patients with bipolar disorder (Gottlieb et al., 2019).
One expert on dark therapy is Norwegian psychiatrist and Ph.D. student Tone Elise Gjøtterud Henriksen. In recent years, Henriksen and her team investigated the application of using orange glasses, which block the blue wavelengths of light. The use of the orange glasses was found to significantly reduce the manic symptoms of the patients participating in the study and in a shorter time than medication (Henriksen et al., 2016).
The result of the previous study formed the basis for several new studies on the use of blue light filtering glasses. In a 2009 study in Chronobiology International, Burkhart and her colleague found that 50 percent of 20 bipolar patients who suffered from insomnia showed significant improvements in sleep after wearing blue-blocking glasses. The majority of those who responded showed not only small but dramatic improvements (Burkhart & Phelps, 2009).
Other studies have shown that exposing bipolar patients to actual darkness at night can have similar results; a 2005 paper found that significantly improved their manic symptoms by placing 16 bipolar patients in darkened rooms for 14 hours a day. But as you can understand, true darkness is much more difficult to achieve and is disruptive to life (Barbini et al., 2005).
The most recent study by Hendriksen and her colleagues showed a large effect of using orange glasses on sleep quality. The intervention group with orange glasses received less intensive sleep-promoting pharmacological treatment and showed significantly higher sleep efficiency and more consolidated sleep compared to the placebo group. Their findings suggest sleep-promoting effects through deactivation mechanisms via dark therapy. Supplementing the existing therapy by means of the orange glasses appears to be useful to improve the sleep of manic patients in hospitals (Henriksen et al., 2020).
Application of dark therapy
Please note that it is not a substitute for medication for bipolar disorder. Always discuss the application of dark therapy with your doctor, psychiatrist, or psychologist. When you wear the glasses, it is as if you are walking around in complete darkness. Visually, you experience the environment with an orange glow, but because your brain does not perceive the blue light, it thinks it is night. The sleep glasses can be applied as follows. Wear the glasses from about 6:00 pm until you get into your bed to go to sleep. Do not wear the glasses in the morning or afternoon.
Please note, do not wear the glasses longer than this. Wearing the glasses longer can disrupt your circadian rhythm and worsen your mood. This is because while wearing the glasses, your body thinks the sun has set, and you don't want it to seem like you're walking around in the dark all day.
And besides, the glasses do not make you sleepy at least not immediately. However, they can help to restore your sleep rhythm so that you can sleep better in the evening and at night. Once your mania has disappeared, you can still wear the glasses, however, it is better to put them on later, about one or two hours before bedtime. In this way, you will experience a natural sunset, without blue light. Just as it used to be, before the invention of artificial lighting.
Blocking blue light for better sleep, how it works.
Sources
Barbini, B., Benedetti, F., Colombo, C., Dotoli, D., Bernasconi, A., Cigala‐Fulgosi, M., ... & Smeraldi, E. (2005). Dark therapy for mania: a pilot study. Bipolar disorders, 7(1), 98-101. https://pubmed.ncbi.nlm.nih.gov/15654938/
Gottlieb, J. F., Benedetti, F., Geoffroy, P. A., Henriksen, T. E., Lam, R. W., Murray, G., ... & Chen, S. (2019). The chronotherapeutic treatment of bipolar disorders: A systematic review and practice recommendations from the ISBD task force on chronotherapy and chronobiology. Bipolar disorders, 21(8), 741-773. https://onlinelibrary.wiley.com/doi/abs/10.1111/bdi.12847
Henriksen, T. E., Skrede, S., Fasmer, O. B., Schoeyen, H., Leskauskaite, I., Bjørke‐Bertheussen, J., ... & Lund, A. (2016). Blue‐blocking glasses as additive treatment for mania: a randomized placebo‐controlled trial. Bipolar disorders, 18(3), 221-232. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5089565/
Henriksen, T. E., Skrede, S., Fasmer, O. B., Hamre, B., Grønli, J., & Lund, A. (2014). Blocking blue light during mania–markedly increased regularity of sleep and rapid improvement of symptoms: a case report. Bipolar disorders, 16(8), 894-898. https://pubmed.ncbi.nlm.nih.gov/25264124/
Henriksen et al., (2020). Blue‐blocking glasses as additive treatment for mania: Effects on actigraphy‐derived sleep parameters. Journal of sleep research, 29(5), e 12984. https://pubmed.ncbi.nlm.nih.gov/31967375/
Kimberly, B., & James R, P. (2009). Amber lenses to block blue light and improve sleep: a randomized trial. Chronobiology international, 26(8), 1602-1612. https://pubmed.ncbi.nlm.nih.gov/20030543/
