Some people suffer from symptoms of depression during the winter months, with the symptoms subsiding during the spring and summer months. This may be a sign of Seasonal Afffective Disorder or SAD, which was noted by doctors more than two hundred years ago but only named within the last twenty years.

As sunlight diminishes during the winter months, a shift occurs in our "biological internal clocks" or circadian rhythms. This can cause our biological clocks to be out of step with our daily schedules. The most difficult months for SAD sufferers are usually January and February, and younger persons and women, according to research, seem to be at higher risk.

If you have noticed a sudden downturn in your mood, or change in sleeping or eating patterns, with the shortening of daylight hours, consider SAD as a possible explanation. Consult with your doctor or a mental health professional about possible treatments, including psychotherapy, phototherapy (or bright light therapy), anti-depressants and seasonal/life changes that may help alleviate symptoms of SAD.