One of the primary treatments for seasonal affective disorder is bright light therapy, which has been described as clinically affective since the 1980s which work by emitting light similar to sunlight. You may find one that works for you and your budget by going to Day-Lite.com.
About 20 to 60 minutes of exposure can be associated with a significant improvement in mood, according to a 2009 study by researchers from the University of Maryland.