CHARLOTTESVILLE, Va. (CBS19 NEWS) -- While Friday's weather did not, in fact, indicate that it is winter, it certainly is. For some people, winter can be associated with a psychological disorder called Seasonal Affective Disorder.

It's a condition in which some people experience a significant mood change when the seasons change, particularly in the fall and winter months. It's considered a type of depression.

Dr. Kim Penberthy, a UVA Health psychologist, says about 10 million Americans suffer from it, with most cases typically seen in middle-aged people and more commonly in women.

Some symptoms include sad, anxious or "empty" feelings, social withdrawal, and irritability and agitation.

Penberthy says one simple way to treat it is just by being in natural light.

"One of the things you can do is get sunlight exposure when you can. I encourage people to get up in the morning, even if you're tired and you feel like sleeping in, get up, get some sun exposure, get outside. We know that helps regulate and improve our mood," she said.

She says to talk to your health care provider or mental health specialist if you are concerned and think you may be suffering from the disorder.