Use of stimulants such as Ritalin, Adderall, and Concerta, intended to treat attention-deficit hyperactivity disorder, has also soared in the past decade. "These drugs are a serious problem, particularly in high schools and universities, because kids think they help them study better," says Gen. Arthur Dean, chairman and CEO of Community Anti-Drug Coalitions of America. "Then, when these overachievers leave college and become high-level young professionals, they carry those behaviors into workforce."

But even older men, who've held down careers for many years, are drugging up to get an extra edge. "Adult professionals are taking these drugs as an enhancement rather than a justified treatment," says Kolodny. "They've functioned just fine all their lives but now they suddenly think they have ADHD symptoms."

These stimulants are highly habit-forming and have several serious side effects. "They can cause hallucinations and raise heart rate too quickly," says Dean. And the longer you're on them, the more problems they can cause. "Taking high doses for a long time can have serious psychological side effects like paranoia, obsessiveness, insomnia, and skin picking," says Kolodny. "Withdrawals are physically milder than with opioids, benzos, or alcohol, but people become very depressed and even suicidal."