| Seasonal affective disorder (SAD) is a type of depression with a recurring seasonal pattern, with symptoms most often starting in late fall and early winter and going away in spring and summer. Several types of treatment for this condition have been studied: A type of cognitive behavioral therapy adapted for use with SAD patients has been shown to relieve symptoms, and its effects may continue into subsequent years, even without additional sessions with a therapist.  Light therapyâwhich involves daily exposure to bright artificial light, usually for 20 to 60 minutes each morningâhas had beneficial effects on SAD symptoms in several studies.  Although low levels of vitamin D have been found in people with SAD, itâs unclear whether vitamin D supplements can help to relieve SAD symptoms. | 