After dozens of parties, numerous family gatherings, and what seems like an entire month off of work, the holidays officially are over. Now it’s back to the grind — for a long, long time.

For many workers, there are only two other paid holidays until the summer — Presidents Day and Memorial Day.

That’s a long time to wait for a chunk of days off, especially after getting used to the past few months with long weekends.

Even if you didn’t travel anywhere exotic for the holidays, numerous studies have shown that taking time off from work helps recharge your energy at the office and reduces stress. But what happens to your psyche when you realize you might not have any paid time off for a while?

I like to call this the post-holiday blues: a work-related slump when you have nothing special to look forward to work-wise. Mondays are severely dreaded. There are no upcoming long weekends. There’s nothing to break up the monotony of tedious tasks, and no way to mentally and physically escape from the dark, cold, and rainy season that doesn’t end until, well, right around Memorial Day.

One simple solution to beating the post-holiday blues, one many people don’t utilize, is taking some vacation time between now and Memorial Day. Expedia’s recent Vacation Depravation study found that the average American worker uses just 11 of the 15 available vacation days most workers receive.

With approximately 122 million full-time workers in the U.S., Expedia’s study says, there are 500 million unused vacation days a year. Reasons workers don’t use their vacation days vary; guilt is one of the most common.

If most of your paid time off happens during the last few months of the year, taking some vacation time during the post-holiday blues period makes sense. Yet many employees leave that PTO on the table, even though it’s obviously needed when there are no holidays in sight.

During the post-holiday blues period, you’re likely to be more stressed out. In 2014, the U.S. Travel Association reported that, “Employees who leave the most PTO unused are also more stressed. Americans who leave 11 days or more unused reported being ‘very’ or ‘extremely’ stressed with their work lives.”

Such stress, Psychology Today points out, “ … takes its toll in part on our body’s ability to resist infection, maintain vital functions, and even ability to avoid injury. Your sleep will suffer, you won’t digest your food as well, and even the genetic material in the cells of your body may start to become altered in a bad way.”

You don’t need to take an elaborate vacation to beat the post-holiday blues. Using your vacation time during the next few months — even in small chunks to enjoy a long weekend once a month — can help you not only do your job better, but also reduce your overall stress level.

I’m sure screwing up your genetic material is not on your list of New Year’s resolutions. So take a vacation. Now.

This article originally appeared in the January 2016 issue of “425 Business.”