The History of Lo-LIGHT Therapy for Mood Disorders

Advances in the Development of Light Therapy

An engineer, Herbert Kern, noticed that his depression appeared at almost the same time each fall and remitted around the same time each spring and believed his mood changed with the seasons. When he read Lewy's report in Science, it occurred to him that his depression might be related to changes in day-length that occurs as the seasons change. He approached Dr. Lewy to see if it would be feasible to use light to treat his depression. Dr. Lewy arranged to extend Mr. Kern's perceived day length in the winter by exposing him to two extra hours of bright light in the morning and in the evening; creating an "artificial summer".

The treatment worked. Within a short period Mr. Kern's depression lifted and the practice of "light therapy" or phototherapy, for the treatment of a seasonal pattern depression was born. Dr. Lewy termed this seasonal depression "Seasonal Affective Disorder", and coined the acronym "SAD", which is commonly used to this day. A milder, sub-clinical condition is known as "The Winter Blues" or "Cabin Fever". Refs.

Light therapy is now the recommended treatment of choice for seasonal depression (SAD) by the American Psychiatric Association. Articles recommending its use to general practitioners have been published by leading researchers from the National Institutes of Health in publications including the Journal of the American Medical Association. Ref

The low-intensity Lo-LIGHT Therapy Lamp

The founders of Sunnex Biotechnologies deduced that wavelength as well as intensity would be a fundamental aspect of light therapy. This was based on their understanding of the nature of biologically significant excitations that result from visible light absorption (i.e. non-ionizing excitations) within living cells. They conducted trials of several ranges of light wavelengths and determined that wavelengths in the shorter region of the green spectrum were by far the most effective for suppressing nocturnal melatonin in humans. They then patented and built a low-intensity light therapy lamp, the Lo-LIGHT, that has proven to be as effective as a bright light therapy lamp at less than 5% of the light intensity as a 10,000 lux bright light therapy lamp.

Validation of the low intensity GreenLIGHT technology

In the early 1990's Sunnex Biotechnologies approached Dr. Lewy to test this new low intensity green light technology. After confirming that tests conducted by Sunnex Biotechnologies indicated that nocturnal melatonin levels could be dramatically suppressed by low intensity of this green light, Dr. Lewy agreed to test the phase shifting ability of this new low-intensity green light on patients with Seasonal Depression (SAD). Dr. Lewy presented the revolutionary results of these studies to the Society for Light Treatment and Biological Rhythms and to the annual meetings of the Sleep Research Society and the American Sleep Disorders Association. Refs

There are now several studies published in major peer-reviewed journals showing that low intensity light from a Lo-LIGHT lamp is as effective for light therapy as high intensity light from a bright light or blue light therapy lamp. See studies showing low-intensity GreenLIGHT as effective as bright light. This is in dramatic contrast to the results of studies with blue light and blue-enhanced light therapy lamps, where several studies have shown that blue light is not more effective or efficient than white light. Refs 1 and Refs 2.
There is now strong evidence that inclusion of blue light wavelengths does not provide any benefit for light therapy. See more evidence on the lack of benefit from blue light.

See clinical studies on the treatment of depression using low intensity GreenLIGHT technology.