BehindTheMedspeak: 'Do you have depression or Seasonal Affective Disorder (SAD)?
...melatonin, a brain chemical turned on by darkness and off by light. Dr. Wehr and Dr. Rosenthal found that the patients with seasonal depression had a longer duration of nocturnal melatonin secretion in the winter than in the summer, just as with other mammals with seasonal behavior
Why did the normal patients show no seasonal change in...



