It's like SAD, but symptoms are to a lesser degree. SAD typically starts in one's early twenties, but can start at puberty or later. It appears to be a genetic trait with entire families being prone to it. At this time a cure is not known, but is treatable. Side effects have been minimal.
Some people have at first experienced anxiety, jitteriness, headaches or early awakening.
Some people may switch to their over-energized summer state. While most of these symptoms disappear within a few days, most can be avoided by starting with a reduced session length or doubling the distance from the light for the first week. Individuals with eye diseases or those using photosensitizing medications should be monitored periodically by an eye doctor. Light therapy has not been shown to cause any eye disease. However, the UV rays posed a health problem with sunburn, eye damage and skin cancer.