Fluctuations in serotonin transport may explain winter blues

Why do many Canadians get the winter blues? In the first study of its kind in the living human brain, Dr. Jeffrey Meyer and colleagues at the Centre for Addiction and Mental Health (CAMH) have discovered greater levels of serotonin transporter in the brain in winter than in summer. These findings have important implications for understanding seasonal mood change in healthy people, vulnerability to seasonal affective disorders and the relationship of light exposure to mood.