Seasonal Affective Disorder is a type of depression caused by seasonal changes. The main thinking around the cause of Winter SAD is that lack of sunlight in the Winter months can stop the hypothalamus in the brain working properly, affecting the production of melatonin, (what is known as) the sleepy hormone.
It is thought that those with SAD produce more of this hormone than those without, causing the individual to feel unusually tired during Winter.
Mental health charity Mind explains Seasonal Affective Disorder (SAD) as:
If you have SAD you may experience some symptoms of depression such as lack of energy, change in sleeping and eating patterns, less interest in seeing people and physical contact and/or feeling tearful, hopeless or anxious at a particular time of year. It is more common to suffer SAD in the Winter but some also notice symptoms in summer and the way it affects sufferers may vary from person to person. Read more…