causes of seasonal affective disorder

Research continues to uncover the causes of seasonal affective disorder. However, scientists believe they are related to seasonal changes on exposure to daylight. A "biological internal clock" in the brain serves to regulate our circadian rhythms (daily) and the production of neurotransmitters that affect our sleep, our mood and our appetite. At the time of distant hunters, sun control activities. People were active when the sun was shining and slept at the sunset. In our modern society, the sun no longer controls our activities. We go to work in the dark and we arrive at home long after sunset. We are working on the inside with poor lighting and we rarely venture into the real light. Although we are unable to follow the sun over our internal biological clock always shows our body to sleep more when the days shorten. This clock has the effect of disrupting the body in relation to our daily work schedule and our family.

Melatonin, a hormone linked to sleep secreted by the pineal gland in the brain, has been linked to seasonal affective disorder. This hormone, which can cause symptoms of depression, is produced at higher levels in the dark. So when the days become shorter and darker, the production of this hormone increases.