1 Redstone SAD light box, 10,000 lux, used as part of light therapy to help alleviate the symptoms of Seasonal Affective Disorder

SAD light boxes or lamps are used to treat Seasonal Affective Disorder. This is a seasonal pattern that can produce a wide array of symptoms including a sense of hopelessness, worthlessness, suicidal tendencies, loss of interest in activities, lack of sex drive, trouble concentrating, sleeping, and socialising, among many others.

The exact cause of SAD is not understood, but it is often linked to reduced levels of sunlight through the winter months. It is suggested that this can cause a lack of serotonin or an abundance of melatonin. SAD lamps are said to work by creating a simulation of sunlight, allowing the melanopsin receptors in the eyes to trigger the release of serotonin.