Dirk Wittenborn’s new novel, Pharmakon, deals with mental imbalance, so perhaps it’s fitting that the book itself has a bit of a multiple-personality disorder. The story’s perspective shifts from William Friedrich, a Yale psychology professor who stumbled on a powerfully Prozac-ish mood enhancer in the early ’50s, to Casper Gedsic, a brilliant student whose trial on the drug goes badly awry, and Friedrich’s son Zach, who’s working through addiction issues while trying to help his family shake off Gedsic’s legacy. Wittenborn’s leaps from third-person to first-person are a little ungainly, making it unclear whose story matters most. But that’s the sort of complication Wittenborn enjoys: In the same way that the word “pharmakon” means both “poison” and “cure,” the novel tests the notion that a high IQ is an unquestionably good thing, chucking the mad-scientist clichés while exploring the slow but certain corrosion that takes place when somebody’s lived too much in his or her own head. WITTENBORN DISCUSSES AND SIGNS COPIES OF HIS WORK AT 7:30 P.M. AT BORDERS, 5871 CROSSROADS CENTER WAY, BAILEYS CROSSROADS. FREE. (703) 998-0404.