Inside Karen’s Crowded Mind

Even for a psychiatric patient, Karen Overhill seemed unusually devoid of hope on the day in 1989 she walked into the Chicago office of Dr. Richard Baer. As weeks of therapy grew into months, antidepressants didn't help her, at least not consistently. She was suicidal—and the flat, emotionless way she stated her wish to die made Baer fear that she might actually follow through. Eventually, Karen began to volunteer stories of childhood abuse. And she mentioned odd memory lapses. She would find herself in strange places with no awareness of how she'd gotten there. She couldn't even remember having had sex with her husband, although she must have, since they had two children.

Baer suspected a much deeper problem than the depression and suicidal thoughts Karen admitted to. Still, he kept his speculation to himself during the first four years of therapy, for fear of planting ideas in Karen's mind. He waited for her to volunteer the information, and in a way, she finally did. In November 1993, an envelope with Karen's return address arrived in the mail. Inside was a single sheet of lined paper and a letter written in a child's penciled scrawl. "My name is Claire," it began. "I am 7 years old. I live inside Karen."

The remarkable medical journey that ensued is the subject of Baer's new book, "Switching Time." It recounts the 17-year course of Karen's therapy in all its painful detail and sheds new light on multiple personality disorder (MPD), the controversial illness that afflicted her. (Karen Overhill is a pseudonym Baer created to protect his patient and her family.) The book describes the challenges Baer faced as more and more of Karen's alter egos emerged—men, women and children—a total of 17, each with his or her own character traits, mental problems and agenda. Baer had to get to know them all, then persuade them to wipe out their individual identities by merging into one. It was the defining case of his career—and one that may have saved Karen's life.

But was Karen's disorder real? There have been allegations that some purported MPD sufferers were just publicity seekers. Yet Baer doesn't have the slightest doubt. As he points out, there are easier ways to gain notoriety than 17 years of therapy. And how could a poseur have maintained each alter's distinct memories, personality, voice and mannerisms for years, never mixing them up? "Meryl Streep couldn't have done it," he says. The alters even wrote him letters in different handwriting.

Still, it's easy to see why MPD remains controversial. Although the condition has been observed for 200 years—and is officially recognized by the American Psychiatric Association under the formal name "dissociative identity disorder"—it is rare enough that most therapists never treat a case. Some psychiatrists doubt that it exists at all, claiming it is the product of suggestion. In some cases, they're probably right. The 1973 best seller "Sybil" led to a wave of diagnoses by therapists who didn't really understand the condition. One psychiatric hospital in Maryland "had a whole ward with patients—some male, some female, some mooing like cows or barking like dogs," says Dr. Paul McHugh, former chair of psychiatry at Johns Hopkins and a leading skeptic. It didn't help that both the made-for-TV movie version of "Sybil," which starred Sally Field, and the 1957 film "The Three Faces of Eve" gave exaggerated portrayals of radical personality shifts, which made MPD seem more bizarre than believable—or that the disorder was later enmeshed in the controversy over false "recovered memories" of childhood abuse. MPD became an embarrassing diagnosis in the psychiatric community.

But it didn't go away. Dr. Frank Putnam—who has studied the condition extensively, first at the National Institute of Mental Health and now at Cincinnati Children's Hospital—continues to receive calls from psychiatrists around the country who are stunned when a patient of theirs turns out to have the disorder. "There's nothing like seeing a patient who has it to make you believe," he says. Today there are clearer diagnostic criteria and a better understanding of the causes. The condition, says Dr. Herbert Speigel, who occasionally treated Sybil during her therapist's absence, is "real, but rare."