Donny Deutsch is a workaholic in recovery.

The chairman and CEO of Deutsch Inc., the largest independent ad agency in the United States, describes his former self as "more than driven; I was obsessed." Over a period of about a dozen years, Deutsch took a total of 15 to 20 days off.

Now, he not only takes vacations, but he typically relies on his seven partners to carry the ball completely while he's out. He's adamant about the importance of time off. "There are companies today that mandate that employees take vacations," he points out. "I don't care whether you're head of a billion-dollar business or a secretary, you need time to clear your mind. It's better if you have a sharp 48 weeks than a blurry 52."

Predictably, the psychiatrists among us agree. It's not just that time off is good for our psyches; it's also good for our companies. "People who think they're doing a good thing for their businesses by working constantly are often doing just the opposite," confirms Dr. Norman Sussman, psychiatrist at NYU School of Medicine. "Vacations restore your perspective. When you get to the point where you can't see the forest for the trees, that downtime gives you the ability to stand back and say, 'Why am I doing this? What am I getting out of it?'"

Additionally, says Dr. Sussman, "Vacations restore family relationships. They enable you to appreciate your partner, they let you know what your kids are all about. People who never get out of work mode usually have terrible personal lives."

Boy, do they. Deutsch, 42, learned that through experience. During those dozen supercharged years, Deutsch succeeded at the office, but the rest of his life fell apart. "I built up a huge business, but my marriage didn't make it; there are certain trade-offs," he says. "In fact, until a few years ago, every woman in my life, including my wife, said the same thing: 'If you could just show me the commitment you show your work, it'd be great.' And it was true, my work always did take precedence."

About six years ago, Deutsch had an accidental revelation when he, for some in-explicable reason, persuaded himself not only to take a vacation, but to leave work worries behind, too. "When I came back, the business was still thriving, and I was sharper than I had been for months," he remembers.

That was the beginning of the end for Deutsch's obsessive ways. And listen up, you vacation skeptics: Since Deutsch's reform, his agency hasn't slowed down. On the contrary. "My business has grown even more, going from about $300 million to a billion-five, "Deutsch adds. "I'm not saying there's an exact correlation, but clearly, just working all the time is not the answer to growth."