If you live a life where you are exposed to a lot of daylight, you are a blessed person from the light perspective. People who spend a lot of time at home or work in the office get too little daylight. Some people keep it up with an afternoon walk and spending a lot of time outdoors in their spare time. But many people suffer from the lack of daylight. It affects their mood. Sometimes in the winter months, it can get so bad that we speak of 'winter depression'. Numerous studies have shown a direct link between depressed mood and the lack of full-spectrum daylight, and True-Light full-spectrum daylight lamps have been used in studies to simulate daylight for decades
The change from light to dark is sensed by the pineal gland through the eyes. Our biological rhythm is adapted to this. To influence the production of melatonin in the pineal gland, light is needed with a power of at least 1000 lux. Our lighting at home or at the office often does not go beyond 200 to 500 lux. Outdoors on a cloudy day, 10,000 lux is reached. This already indicates why our body slides into the winter dip in the winter months if we don't get outside enough. Winter depression comes in many variations, from sleeping poorly and feeling tired to barely sleeping and feelings of deep depression.
There have been a lot of studies on winter depression, but we'll take one of the first studies, that of N.E. Rosenthal "Seasonal Affective Disorder: A Description of the Syndrome and Preliminary Findings With Light Therapy" from Archives General Psychiatry, '84, pp 72-80, as an example. Both patients and researchers were not yet aware that full-spectrum daylight is beneficial. This study was done double-blind on two groups of people with seasonal depression. Each group was exposed to either full-spectrum daylight lamps or to "normal" artificial light, which was soft yellow in colour, for six hours a day for two weeks. Each group was then exposed to the light source to which they had not yet been exposed for another two weeks. None of the researchers (to get a double-blind study) knew what light the patients were exposed to. The patients did not know which light source was considered to be beneficial. The results were overwhelming. All patients had a major improvement during treatment with full spectrum daylight lamps, while none showed an improvement with the treatment of the soft yellow lamps. The patients said that after the treatment with the full-spectrum daylight lamps, they had the impression that they had awakened from hibernation. They felt an urge to act and were able to resume their normal activities. This was the beginning of many studies confirming what the initial study had shown, but this research also sparked whole new therapeutic approaches that have expanded far beyond the world of psychiatry.
If you can't go outside for a few hours every day, full spectrum daylight lamps are a good solution for treating winter depression. To achieve a good result, it is important to sit or work for several hours under full-spectrum daylight lamps every day.