Have you heard of the Rosenhan experiment, conducted back in the 1970s to determine the validity of psychiatric diagnosis?
“The experimenters feigned hallucinations to enter psychiatric hospitals, and acted normally afterwards. They were diagnosed with psychiatric disorders and were given antipsychotic drugs. The study was conducted by psychologist David Rosenhan, a Stanford University professor, and published by the journal Science in 1973 under the title ‘On being sane in insane places’. It is considered an important and influential criticism of psychiatric diagnosis.
Rosenhan’s study was done in two parts. The first part involved the use of healthy associates or ‘pseudopatients’ (three women and five men, including Rosenhan himself) who briefly feigned auditory hallucinations in an attempt to gain admission to 12 different psychiatric hospitals in five different states in various locations in the United States. All were admitted and diagnosed with psychiatric disorders. After admission, the pseudopatients acted normally and told staff that they felt fine and had no longer experienced any additional hallucinations. All were forced to admit to having a mental illness and had to agree to take antipsychotic drugs as a condition of their release. The average time that the patients spent in the hospital was 19 days. All but one were diagnosed with schizophrenia ‘in remission’ before their release.
The second part of his study involved an offended hospital administration challenging Rosenhan to send pseudopatients to its facility, whom its staff would then detect. Rosenhan agreed and in the following weeks out of 193 new patients the staff identified 41 as potential pseudopatients, with 19 of these receiving suspicion from at least one psychiatrist and one other staff member.
In fact, Rosenhan had sent no pseudopatients to the hospital …”
You can read more from Wikipedia about this here.