Is there such a thing as 'spring fever'?

Now that it's no longer so cold and dark, do you have a big smile on your face? Do you have the urge to skip work and lay in the grass?

Two University of North Carolina medical professionals looked at the phenomenon and say: yes, seasons do affect our mood. And "spring fever" is real.

Well, sort of.

"It depends on what you mean by 'real,'" Jon Abramowitz, professor and associate chair of psychology at the University of North Carolina, told the university.

"When the weather turns warm, people are definitely tired of being cooped up, and they get excited about the warm weather and getting to do stuff outside," he said.

According to the university, he says excitement may trigger the brain to secrete endorphins. Those are the chemicals that give you that sense of well being. They chemically resemble morphine, the narcotic derived from poppies.

Exercise may also contribute to spring fever: "Exercise is just as good as antidepressants for depression," Abramowitz said.

Dr. Thomas Koonce, associate medical director at the UNC Family Medical Center, told the university that more sunlight may just help end the winter blues. Lack of daylight can cause depression because of changes in levels of melatonin, which helps regulate sleep.

He added that there isn't much scientific evidence that spring puts people in the mood for love.

There isn't much evidence that spring put people in the mood for love, he said, but people do feel better and more energetic when it's warm. (Studies show sperm counts are actually the lowest during hot summer months.)

The university says research shows a small peak in births in February, meaning people got romantic the previous spring. But more babies are made in winter because more are born in August and September.

Some tips for a healthy and happy spring from the university:

Exercise 20 to 40 minutes most days of the week outside;

Exercise in the early morning to avoid the worst of the pollen, and stay well hydrated;

Resume exercise gradually to avoid injury;

Wear protective clothing and sunblock, and stay inside during the sunniest hours to avoid the cancer-causing rays.

(c) 2010, The Baltimore Sun.