In order to observe the societal perception of those with mental illness, David Rosenhan conducted an observational study. In 1973, there was a problem with properly diagnosing patients and their mental illness.  In 1973, David Rosenhan sought out to see what would happen if he placed pseudopatients in psychiatric hospitals and assessed how they were treated.

http://https://www.youtube.com/watch?v=j6bmZ8cVB4o%20

By placing eight individuals who have not been diagnosed with a mental illness in 12 different psychiatric wards across the country, Rosenhan observed how the individuals were treated while in the ward as well as after their discharge and how many days they stayed in the ward. The staff was unaware of the experiment and were under the assumption that the pseudopatients were experiencing signs of schizophrenia such as hearing voices which were unclear at times and they felt as though life was empty and hollow.

After admission, the pseudopatient ceased showing signs of their symptoms and behaved as though they would typically behave. They were unaware of when they would be discharged and had to be discharged through their own actions which took from 7-52 days.  The patients were not detected as not suffering from schizophrenia but were discharged due to their good behavior and cooperation. Each of the patients were discharged with schizophrenia in remission.

https://isites.harvard.edu/fs/docs/icb.topic625827.files/On_Being_Sane_In_Insane_Places-1.pdf