Sleep duration, for example, may be normal, while carbohydrate craving may be extreme, or vice versa. Sometimes a symptom in the cluster is actually opposite the norm, such as insomnia as opposed to excessive sleep. These people notice the return of SAD-like symptoms each winter, and are bothered by them, but remain fully functional. Exposure to bright light effects changes in a person's circadian rhythms. Thousands of people find relief through bright light therapy, although the physiological mechanism is still uncertain.
Light therapy involves exposure to intense levels of light under controlled conditions.
Our technologically advanced lightbox is set up on a table or desktop at which one can sit comfortably for the treatment session. Treatment consists simply of sitting close to this light. What is important is to orient your head and body toward the light, concentrating on activities illuminated by the lights, and not on the lights themselves. Treatment sessions can last from fifteen minutes to three hours, once or twice a day, depending on individual needs. The time of day for light therapy is an important factor.