Though many psychiatrists have abandoned the "chemical imbalance" concept, they now promote the use of a pre-scientific notion that the only criteria for defining disease is the presence of distress or impairment.
Dr. Pies' summary of Schroder et al's study is misleading. In fact, the researchers found that the more times a person was hospitalized, the more likely they were to believe the chemical imbalance myth.
Dr. Pies claims that the "chemical imbalance" theory was never really professed by psychiatrists. Yet he himself wrote an essay in "Creative Nonfiction" in 1999 that purveyed it directly to the layperson.