The Rosenhan experiment was an experiment conducted to determine the validity of psychiatric diagnosis and remains one of the most important anti-psychiatry studies. In the experiment, eight “normal” and mentally healthy researchers tried to gain admission, through diagnosis, to some American mental hospitals. They did that by feigning hallucinations and claiming that they heard voices. Seven were diagnosed as schizophrenic and admitted. Once in the hospital they behaved normally and were ignored when they politely asked for information. They later reported that their dialogist label of schizophrenia meant they had low status and power in the hospital.
Later on, they came clean and admitted they had no symptoms and felt fine. But it took nearly three weeks before they were discharged, often with the diagnosis “schizophrenia in remission.” So normal, healthy people could easily be diagnosable as “abnormal.” But could the reverse happen? The same researchers told the psychiatric hospital staff that fake, or pseudopatients, pretending to be schizophrenic may try to gain access to their hospital. They then found that 19 genuine patients were suspected as frauds by two or more members of staff, including a psychiatrist. The conclusion was that it is not possible to distinguish the sane from the insane in mental hospitals. Though this famous study has received considerable criticism on ethical and experimental grounds, it played a big role in the anti-psychiatry movement.