RENO, NV -- Seasonal Affective Disorder, also known as “SAD” is typical this time of year. This mood disorder shows people get the winter blues at the same time every year.

Physiologist Kristen Davis- Coelho says the causes of SAD aren’t exactly known.  “But they do believe it’s related to circadian rhythms, the amount of sunlight, and what that does to the biological changes in the brain,” Davis- Coelho  said. “And you’ll see higher incidents of this in areas where they have lower levels of sunlight in the winter and longer winter nights.”

Rosie Rotberg recognizes that.“You know I even notice sometimes with the loss of daylight you kind of get a blue every once and awhile,” Rotberg said. “Because the sunshine is cheerful.”

Some symptoms of SAD include loss of interest, less energy, social withdrawal, and weight gain. Experts say about 90 percent of people with SAD experience depressive symptoms yearly in the fall and winter, while about 10 percent have depression in the spring and summer.

Randy Wilkinson can relate. He tells us he gets the winter blues sometimes.  “But I try and get of it, you know,” Wilkinson said. “I work out or go skiing or run or whatever it takes.”

Davis- Coelho says that’s exactly what you should do.  “If you can’t go outside a lot, if you’re in doors most of the day, changing your environment so that you have more light in your environment, open the blinds, sit by the window, put in bright lights,” Davis- Coelho said.

She also suggests resisting the urge to isolate and avoid people.  “The more you can actually force yourself to do things that you usually would enjoy, to spend time with people that you know are supportive, the better off you’re going to be,” Davis- Coelho said.

If these strategies aren’t effective, experts suggest consider meeting with a therapist or psychiatrist.