(NBC) -- If you're feeling run down, cranky or a little depressed these days you may be suffering from something called "PVS" -- Post Vacation Syndrome.
PVS isn't found in any reputable medical journals, but it's gaining attention among psychologists who say they really do see a spike in people in need of help every year around this time.
"You start having people complain almost immediately, right around this time of year, right after Labor Day, people are anticipating a change in the weather," says the Cleveland Clinic's Dr. Scott Bea.
A few weeks ago, you were boogie boarding with the kids.
Now those are kids are back in school, which means parents are busy helping with homework and after-school activities.
Temperatures are starting to dip and the sun is setting earlier.
"The lack of sunshine seems to help us produce melatonin, makes us feel sluggish, more lethargic, we start to eat a little more," explains Dr. Bea.
Dr. Bea says one way to beat Post Vacation Syndrome is to get moving.
In fact, a recent study found exercise may work as well as an antidepressant for some people.
And just because the big summer vacation is over doesn't mean you can't work in a few mini-breaks.
Change can be good, even if you go from walking the dunes to pounding the pavement.
You might need to seek professional help if you go for more than two weeks feeling hopeless, or stop functioning well either socially or at work.
Also be on the lookout for changes in appetite, weight and sleep patterns.