I’m one of those people who thinks they work well under deadlines.

In fact, I can barely get things done without deadlines. When I have only 2 hours to get something done, it gets done in 2 hours. If I have can get it done anytime, it’ll never get done.

Unfortunately, that task-oriented part of the brain is not what comes up with original ideas, according to research by Dr. Richard Boyatzis of Case Western Reserve University. When we’re stressed, our prefrontal cortex, associated with concentration, abstracting ability, judgment, and interacting with others, goes dim.

When even the very smartest and most well-adapted people are stressed, they enter a state of cognitive, emotional, and perceptual impairment. They may push forward with completing tasks out of habit. If they worked with less stress, they could come up with innovative solutions to the problems in front of them that could make their work better -- and possibly even easier.

But what about all those people who say, “I perform best under stress”? Boyatzis found that unless your best work is habitual, dull, or robotic, this is physically impossible. "The research shows us that the more stressful a deadline is, the less open you are to other ways of approaching the problem," Dr. Boyatzis told the Wall Street Journal.

Even more alarming, when we’re constantly in stress mode (what researchers call “chronic stress”), it can permanently impact our brains. You’ve probably heard the phrase “stress makes us stupid.” But this isn’t just a short-term result; stress kills brain cells.

“Chronic stress—or being stressed for a long time—actually ends up killing brain cells and shrinking parts of the brain that are extremely important for thinking and learning,” says William Stixrud, Ph.D., a clinical neuropsychologist.

Chronic stress can also have long-term impacts on your mental health. “You also see shrinkage in the prefrontal cortex resulting from chronic stress, whereas the amygdala, the part of the brain that detects threat, starts working overtime and actually gets bigger. Thus, the more anxious and stressed you are, the more anxious you become.”

As freelancers and entrepreneurs whose businesses thrive off creative and out-of-the-box brain power, these studies should give us a good kick in the rear to finally get our lives into greater balance. Meditation, yoga, exercise, and other stress-reducing practices are no longer “nice-to-haves” -- they’re crucial for keeping our brains healthy and our ideas fresh.