The problem was that most of these diagnoses had been created by doctors arguing in a conference room; there was no blood test for schizophrenia or manic depression. Despite decades of searching for genetic and environmental factors, we still don’t know what causes these disorders or even whether they are distinct diseases. As one psychiatrist puts it in Cahalan’s book, today, “Symptoms and signs are all we fundamentally have.”

Rosenhan isn’t the only social scientist whose work at the time has come under ethical scrutiny. His Stanford colleague Philip Zimbardo, the author of the famous “prison experiment,” in which a simulation involving students posing as “guards” and “inmates” spun violently out of control, was recently found to have coached the “guards” to behave more aggressively — tainting the study’s conclusions about prison’s inherent evil. But “The Great Pretender” leaves open the possibility that Rosenhan did more than distort and omit facts that undermined his thesis. Could he have invented the other pseudopatients out of whole cloth?

“This was one of the handful of the most influential social science papers produced since World War II and ironically it’s a fraud,” Scull said. “It’s possible, now that the book is coming out, that someone will emerge from the weeds and say, ‘Actually, my aunt was one of those pseudopatients.’ But even were pseudopatients to surface this point, the other evidence Susannah lays out is so damning that it wouldn’t transform things.”

Cahalan is more circumspect. “I believe that he exposed something real,” she writes toward the end of her book. “Rosenhan’s paper, as exaggerated, and even dishonest as it was, touched on truth as it danced around it.”

His message about psychiatry’s limitations helped her understand how her own ordeal could have turned out so differently from that of her mirror image.

“I was a medical marvel,” she said. “The more access I got to psychiatry, the more I realized that I was a marvel and that the average person isn’t and won’t necessarily get the outcome that I did. This was a recalibration for me, to put my experience in the proper context: that it was extraordinary.”