Despite recent bad publicity over withheld studies showing marginal results, the resume of America's arsenal of antidepressants is enviable: consort to celebrities, subject of best-selling books and tabloid headlines. They may be the most celebrated pills since Valium. Prozac, Zoloft, Paxil, Celexa and Lexapro, among others, have become both household words and medicine-cabinet staples. Known collectively as selective serotonin reuptake inhibitors, or SSRIs, these antidepressants are prescribed for anxiety, social phobia, obsessive-compulsive disorder and numerous conditions besides depression. SSRIs are now the most commonly prescribed of all medications in this country. The rate at which physicians prescribed SSRIs more than...