The history of the United States is a history of neurosis, Andrea Tone explains in her lively and thoughtful history of tranquilizers, "The Age of Anxiety." The pills and their targets may change -- Miltown for the harried businessman in the '50s, Valium for the stressed-out mom in the '60s, Paxil for seemingly everybody today. But the core problem of managing work, home life and glum headlines has always been a part of our lives. William James had a word for it back in the late 1800s: Americanitis.

"The Age of Anxiety" largely covers the two most important tranquilizer pills of the 20th century: Miltown, first marketed in 1955, and Valium, which arrived in 1960. Like many medical breakthroughs, Miltown was an accident. Its creator, Frank Berger, was working with a chemical designed to extend the life of penicillin -- back before they became corporate behemoths, pharmaceutical companies had a hard time keeping up with demand -- when he discovered its possibilities as an anti-anxiety drug.

The pill filled an enormous need. The psychiatrist's couch was too expensive for most Americans, and the other drug of choice, barbiturates, was addictive and unreliable. Although it's practically unknown today, Miltown was a blockbuster in its time, thanks largely to the celebrities who routinely sang its praises. Milton Berle often referred to himself as "Uncle Miltown" on his variety show, and Tone shows numerous instances of the drug insinuating itself into pop culture, from greeting cards to an odd Miltown-themed art installation by Salvador Dali that was presented at a medical conference.

So where did the stigma of popping tranks come from? To some extent, pharmaceutical companies subtly encouraged it by employing a double standard. While Miltown was marketed as a responsible choice for the hard-working male city dweller (its nickname was "executive Excedrin"), Valium was sold to women, Tone writes, "as a quick fix for the problem of simply being female." The book shows a Valium ad in a medical journal telling the story of an apocryphal woman who could use the drug because she's 35 and unwed. Shaming tactics weren't the only issue. Valium (and its close cousin Librium) are benzodiazepines, more powerful than Miltown but also more addictive. When that fact made the news, driven largely by Barbara Gordon's 1979 bestselling memoir, "I'm Dancing as Fast as I Can," Americans began to distrust the drug's promises. A worried nation was now anxious about its anxiety pills.

Of course, that hasn't stopped Americans from taking them. Most anti-anxiety prescriptions in 2006 were for benzodiazepines, Tone reports, and they're joined by a universe of newer pills such as Xanax, Paxil, Prozac and more. Tone, a professor of the social history of medicine at McGill University, is a diligent researcher, and she deftly covers the tangle of historical, medical, legal and cultural issues here without lapsing into jargon -- no easy feat with a subject like this. The book's main shortcoming is that it largely rushes through the years following Valium's scandalization. Tone's richly analytical chapters on Valium and Miltown could stand to be matched by a couple that give SSRIs the same treatment. Or, perhaps, their own book. After all, the market for them will be there; as Tone makes abundantly clear, the age of anxiety is eternal.

Mark Athitakis is a writer in Washington, D.C. He blogs at americanfiction.wordpress.com.