Either type of SAD may also include some of the symptoms that occur in major depression, such as feelings of guilt, a loss of interest or pleasure in activities previously enjoyed, ongoing feelings of hopelessness or helplessness, or physical problems such as headaches and stomach aches.
Insufficiency of vitamin D is associated with clinically significant depression symptoms.
There are several factors known to increase an individuals chance of developing SAD.
Some people experience symptoms severe enough to affect quality of life, and 6 percent require hospitalization.
Many people with SAD report at least one close relative with a psychiatric disorder, most frequently a severe depressive disorder (55 percent) or alcohol abuse (34 percent).
For example, SAD is more frequent in people who live far north or south of the equator.
Additionally, people with a family history of other types of depression are more likely to develop SAD than people who do not have such a family history.To be diagnosed with SAD, an individual must meet criteria for major depression coinciding with specific seasons for at least two years.The individual must experience seasonal depressions much more frequently than any non-seasonal depressions.Doctors first noticed this opposite, annual winter depression, 150 years ago, but the condition remained a theory until the early 1980's, when researchers began linking the darkening of people's winter moods to the lack of sunlight from November through March.Today, this condition is known as Seasonal Affective Disorder (SAD).They helped, but Owens still "felt out of it." One day in 1982, Owens saw a television show about depression.It talked about the study of a new kind of depression, called Seasonal Affective Disorder, that struck people around the same time every winter, and caused other symptoms, like winter weight gain and the desire for sleep. To be diagnosed with SAD, the changes in mood should not be a direct result of obvious seasonal stressors (like being regularly unemployed during the winter).Usually, this form of depression is mild or moderate.Seasonal affective disorder is estimated to affect 10 million Americans.Another 10 percent to 20 percent may have mild SAD.