Diagnostic labeling in mental health refers to the process of identifying and naming mental health conditions based on a set of symptoms and criteria. Diagnostic labeling is a critical concept in David L. Rosenhan’s study, which examines the impact of psychiatric labels on the perception and treatment of individuals. The essay demonstrates how labels can lead to biases in treatment and the misinterpretation of “normal” behaviors as pathological; Rosenhan argues that the application of a diagnostic label can overshadow the individual’s true identity and needs, resulting in Stigmatization and Dehumanization in Mental Health Care.

“Pseudopatient” is the term Rosenhan uses to describe the individuals who pretended to have a mental illness for the purpose of his study. The concept of the pseudopatient—that is, the assumption that certain people are “really” mentally healthy—is central to the experiment, as it serves to test the legitimacy of psychiatric diagnoses and the hospital environment’s response to mental illness. Rosenhan argues that the pseudopatients’ persistent misdiagnosis exposes the flaws and biases in psychiatric practices and The Unreliability of Psychiatric Diagnoses.

“Sanity” is a loosely defined term; in popular parlance, it refers to the state of being mentally healthy, but it has no clinical definition.