A reliable and valid diagnosis is one which is correctly reasoned from a satisfying premise and agreed upon by psychiatrists using the same diagnosis system.
However, there are many factors that make the process of determining a diagnosis intricate. For one to obtain a reliable and valid diagnosis, one has to be sure that the classification systems themselves are valid and reliable. Because the concept of abnormality is so complex it is particularly difficult to define and this affects diagnosis. Also, there are a number of cultural and ethical considerations one must consider when making a diagnosis, some of these include culture-bound syndromes, culture blindness and racial/ethnic bias. Though many errors with diagnosis have been occurred, one cannot ignore the benefits of diagnosis and the medical breakthroughs
When determining a diagnosis psychiatrists refer to one of three classification systems, the DSM-IV, the ICD and the Great Ormond Street System. For a classification system to be reliable, it should be possible for different clinicians, using the same system, to arrive at the same diagnosis for the same individual. For a classification system to be valid, it should be able to classify a read pattern of symptoms which can then lead to an effective treatment. However, it has been researched and statistics show that no classification system has a 100% reliability rate. In fact, it was found that the ICD had a reliability of 36%, the DSM had a reliability of 64% while the Great Ormond Street System had a reliability of 88%
The Rosenhan study illustrates the concerns about reliability in diagnosis of psychiatrist illness. The experiment consisted of two parts; the first part involved the use of 12 mentally stable people (pseudopatients) who tried to gain admission into 12 different psychiatric hospitals by complaining of ‘hallucinations’. All the researchers were admitted and diagnosed with psychiatric