Feeling blue and depressed during the dark, cold winter months? According to a study published in the Brittish medical journal, The Lancet (December 7,2002;360:1840-1842), this dip in mood may be caused by lowered levels of serotonin, a chemical in the brain. Serotonin levels are low in people with depression and also in healthy people during the winter (SAD).

In the study, blood samples were taken from blood vessels leading to the brain in 101 healthy men at several different times over a one year period. Results indicated that the activity of serotonin-containing neurons was lowest during the fall and winter and highest in the spring and summer, when sunlight is most plentiful.

In the study, serotonin neuron activity was higher on brighter days than darker days, even within the same season. This suggests that levels of serotonin in the brain were directly related to how much sunlight was available on the day the sample was taken. Though this study involved men, researchers say that women likely experience a drop in serotonin levels during the winter as well, though the actual amount may differ according to gender. Additionally, researchers note that results point to a biological reason for SAD, which may help to displace some of the skepticism regarding this, and other, mental illnesses.

In treating sufferers of SAD, patients are exposed to bright light, a technique known as phototherapy. Since serotonin levels rise in the brain on bright days with a lot of sunlight, bright light may boost mood by activating neurons in the brain that contain serotonin, leading to increased levels of the chemical in the brain, according to the researchers.

Learn More About SAD and Light Therapy

---

 

 

 

 

 

Disclaimer

Tanning & Natural Health News is a publication of Tan Plus /Essentials Of Life, Barclay Square, 350 Route 108, Somersworth, NH. This publication is designed for educational purposes only and is not intended to be presented as medical advice. Product statements made have not been evaluated by the Food & Drug Administration.