Performance anxiety is among the most widespread of phobias; by some measures, it afflicts up to 20 percent of Americans. That group includes a striking number of people who perform for a living. Barbra Streisand developed overwhelming performance anxiety at the height of her career; for 27 years she refused to perform for the general public, appearing live only in private clubs and at charity events, where she presumably believed the pressure on her was less intense. Carly Simon abandoned the stage for seven years after collapsing from nerves before a concert in Pittsburgh in 1981. When she resumed performing, she would sometimes ask members of her band to spank her before she went onstage, to distract her from her anxiety. The singer Donny Osmond had panic attacks during performances for a number of years. (He is now a spokesman for the Anxiety and Depression Association of America.)

The comedian Jay Mohr tells a story about frantically trying to smuggle a Klonopin onstage to stave off what he feared would be a career-ending panic attack while performing a skit on Saturday Night Live. (What saved Mohr on that occasion was not the Klonopin but the distracting hilarity of his sketch mate Chris Farley.) Hugh Grant, who several times has announced that he was thinking of retiring from acting, has said that he suffers from panic attacks when the cameras start rolling. He survived one film only by filling himself “full of lorazepam,” a sedative with the trade name Ativan. “I had all these panic attacks,” he said. “They’re awful. I freeze like a rabbit. Can’t speak, can’t think, sweating like a bull. When I got home from doing that job, I said to myself: ‘No more acting. End of films.’ ”

Ricky Williams, who won the Heisman Trophy in 1998, was known to suffer from severe anxiety; social interactions made him so nervous that he would give interviews only while wearing his football helmet. Laurence Olivier, convinced that his stage fright was about to send him into what he was sure would be reported as a “mystifying and scandalously sudden retirement,” finally confided his distress to the actress Dame Sybil Thorndike and her husband. (“Take drugs, darling,” Thorndike told him. “We do.”)

Then there are notable figures from history. Demosthenes, a Greek statesman renowned for his oratorical skills, was, early in his career, jeered for his anxious, stammering performances. Cicero, the great Roman statesman and philosopher, once froze while speaking during an important trial in the Forum and had to cut short his remarks. “I turn pale at the outset of a speech and quake in every limb and in all my soul,” he wrote.

In 1889, a young Indian lawyer froze during his first case before a judge and ran from the courtroom in humiliation. “My head was reeling and I felt as though the whole court was doing likewise,” the lawyer would write later, after he had become known as Mahatma Gandhi. “I could think of no question to ask.” Another time, when Gandhi stood up to read remarks he had prepared for a small gathering of a local vegetarian society, he found that he could not speak. “My vision became blurred and I trembled, though the speech hardly covered a sheet of foolscap,” he recounted. What Gandhi called “the awful strain of public speaking” prevented him for years from speaking up even at friendly dinner parties, and nearly deterred him from developing into the spiritual leader he ultimately became.

Thomas Jefferson, too, had his law career disrupted by a fear of public speaking. One of his biographers notes that if he tried to declaim loudly, his voice would “sink in his throat.” He never spoke during the deliberations of the Second Continental Congress and, remarkably, according to Joshua Kendall’s book America’s Obsessives, gave only two public speeches—his inaugural addresses—during his years as president. After reviewing presidential biographies and other materials, psychiatrists at Duke University, writing in The Journal of Nervous and Mental Disease, diagnosed Jefferson posthumously with social phobia.