Seasonal Affective Disorder (appropriately named SAD or the Winter Blues) can be serious, but is a very treatable form of depression which can occur each year, starting in fall or winter and ending in spring or early summer. The mood disorder is triggered by the reduction of sunlight during the winter months. While those who move to Chicago from sunnier climates may be prone to this, many who live all their lives in the midwest or northern climates can suffer from SAD as well. The first episodes are most likely to appear in individuals during their early twenties. A true diagnosis can usually be made after an individual has experienced winter depression for two years running. However, depression of any type is a serious illness which can affect many systems in the body, as well as all aspects of a person's life. It's important to get professional consultation and treatment as soon as possible. Don't suffer through two years of this winter illness to be sure it's SAD.
For more information about depression and Seasonal Affective Disorder click here: http://www.mayoclinic.com/health/seasonal-affective-disorder/DS00195