In 1692, three adolescent girls who lived in the Massachusetts Bay Colony began acting strangely.  They had inexplicable episodes of screaming, twitching, babbling incoherently and even convulsing. When they were asked by the town elders to account for their unusual behavior, the frightened girls identified...

Every January my clinic schedule fills up with patients who, in keeping with their New Year’s resolutions, want to lose weight, drink less alcohol, and stop smoking. In my first few years of practice, I felt obligated to give each of these patients a 20 minute lecture on their vice of choice, replete...