Rosenhan (1973) who claimed that situational factors were more important in determining the diagnosis of schizophrenia rather than any specific characteristics of the illness. This shows clearly that the diagnostic procedure used at the time was flawed.
Rosenhan arranged for pseudo patients to present themselves to psychiatric hospitals in the US claiming to be hearing voices in their heads, a classic symptom of schizophrenia.
All were diagnosed with schizophrenia despite the fact that they displayed no further symptoms during their hospitalisation, with none of the staff recognising them to be normal.
This points to a lack of reliability in the classification and diagnostic system of schizophrenia.
Rosenhan further demonstrated the unreliability of diagnosis in a follow- up study where he warned hospitals of his intention to send out more pseudo patients. This resulted in a 21% detection rate, even though there weren’t any pseudo patients sent. This means that real patients missed out on being treated and it provides further evidence that there are issues with the reliability of the classification and diagnostic system of schizophrenia.
- issue of the research being outdated - no longer such issues of diagnosis due to classification systems being continually updated
- very high ecological validity - carried out in real hospitals with real staff who were unaware of the study
- cultural bias - conudcted in the US, therefore cannot be assumed that people from other cultures will behave in the same way
- ethical issues - all staff were deceived about patients symptoms -> could neither give consent nor exercise right to withdraw.