Winter is done.  That's a reason to smile.  But the change in seasons may be helping you grin a bit more.  In fact, soome refer to spring as "nature's anti-depressant."  Cleveland Clinic Psychologist Dr. Scott Bea says part of the reason the beginning of  spring is such a "pick-me-up" is because of what winter does to us.

"In the winter our ability to recreate, to get with other people, to engage in leisure-time activities is really reduced," he said.

University of Michigan researchers have studied how mood and mental health can be impacted by the weather. They found a correlation between warmer, sunnier days and improved mood.

Humboldt University Researchers in Germany also studied the way weather affects us. They found there are some people who truly are not affected by the weather, but lots of us can experience joy or depression based on what's going on outside.

Researchers say the findings suggest our moods are at least somewhat sensitive to weather conditions. Bea says, after the winter we've had, some folks may be in need of a 'mental health day'.

"The classic mental health day is probably taken when someone is feeling a little bit pinched or feeling they need a little compensation for the suffering in their life and, of course, this winter has had a lot of people feeling that suffering," he said.

A lack of vitamin D, which we get from the sun, has also been tied to depression, so just getting out and feeling the sun may improve your mood, too.