Diagnosis is when botanists look at one particular flower and decide thats it characteristics identify it as a rose (as oposed to a tulip). In the field of mental health, diagnosis is the clinical judgement that a particular person is suffering, for example from depression.
Reliability of psychiatric diagnosis is the extent to which a classification system repeatedly produces the same outcome. More specifically in relation to mental health workers, inter rater reliability is the extent to which two independent clinicians agree about the diagnosis of a person using the DSM as criteria with a mental health problem such as depression. Validity of the systems in measuring what they set out to measure (the correct symptoms and duration) for diagnosis of depresion. They should make sure the universal definition will match to someone who has depression and if they do not have enough symptoms or similar symptoms then they cannot be classified as having depression.
Rosenhan's study has changed the classifications systems vastly. Nine healthy people presented themselves at different psychiatric hospitals and said that they were hearing voices saying things like 'empty and 'thud'. All were admitted and all, except one were diagnosed as suffering from schizophrenia. Apart from changing their names and jobs, all other information given to the clnicians at the hospitals thereafter was true. As soon as they were admitted to psychiatric wards, all eight stopped simulating any symptoms of abnormality.
The pseudopatients were never detected and were eventually discharged with the diagnosis of schizophrenia in remission. Length of hospitalisation ranged from 7 to 52 days (average 19). Perhaps most interesting though, is the fact that several fellow patients (35 out of 118 in the first three hospitalisations, when detailed records were kept by the pseudopatient) 'detected their sanity'.
On the basis of what happened in each of these cases, Rosenhan suggested that psychiatrists are unable to determine who is and who is insane. Rosenhans study made a deep impact on the classification of mental illness and was taken into account in tightening up the guidelines for diagnosis of schizophrenia under the DSM system.
Hearing voices is the most common symptom of schizophrenia and all the patients reported this as the problem. We need to consider the difficult position that the clinicians were placed in, since the consequences of sending someone away who might be seriously mentally ill is likely to be much worse than the repercussions of admitting someone into hospital who turns out to be mentally well. This study is based on schizophrenia but demonstrates how unreliable the DSM is overall in diagnosis so a study for depression could be similar e.g. All patients saying they have suicidal thoughts would be similar in results and doctors could not turn them away.
Davison outlines that issues with classification systems are specifying a particular number of symptoms from a longer list that must be evident before a particular diagnosis can be made. For example, DSM-IV-TR(2000) insists on depressed mood plus 4 other symptoms to be present to diagnose MDD. But why four? This has been increased to five in 2010. Why five?
There is still room for subjectie interpretation on the part of the psychiatrist. For example the DSM requirews comparison between the patient and an 'average person'. These examples beg all sorts of questions. As Davison (2004) argues 'such judgements set the stte for the insertion of cultural and gender biases as well as the clinicians own personal ideas of what the 'average person' should be doing at a given stage of life.
Conctruct validity is the most relevant form of validity in relation to diagnosis. Construct validity is determined by evaluating the extent to which accurate statements and predictions can be made about a category. In relation to mental illness this is looking at; Possible caues (such as genetic predisposition or biochemical imbalance), Characteristics of the disorder that aren't symptoms as such but are associated with it e.g. low self esteem in depression and predictions about the course of the disorder and probable response to particular treatments.
Davison et al believes that the DSM diagnostic categories do indeed possess some construct validity. However, these are threatened by cultural and gender bias. The reliability and validity of various forms of psychological assessment have been questioned on the grounds that their content and scoring procedures reflect the culture of white europeans and may not accurately assess people from other cultures. One way in which cultural biases may work is by causing psychiatrists to over- or underestimate psychological problems in members of other cultures. For example, not only are afro-caribbean people in the UK more likely to be diagnosed schizophrenic or compulsorily committed to psychiatric hospital, they're also more likely to be given major tranquilising drugs or electroconvulsive therapy than white people. This is mirrored in a study by Blake which showed that clinicians were more likely to diagnose a patient as having schizophrenia if the case summary referred to the person as afro-caribbean than if he/she was described as white.
All ethnic minorities are far likely to be referred for psychotheraphy than indigenous whites, and similar differences have been reported between middle class and working class groups. Women are also more likely than men to be diagnosed as mentally ill. Should a very emotionally withdrawn Asian-American be perceived as displaying characteristics that are judged more positively in Asian cultures than Euro-American culture, or be seen as having a psychological disorder? A clinician who attributes this behaviour to a cultural difference rather than to a psychological disorder risks overlooking an emotional problem that he/she would be likely to diagnose if the patient were a white male.
An attempt to improve the reliability and validity of the DSM is the Composite International Diagnostic Interview, developed in Australia by Andrews and Peters. Patients/clients work through a highly structured interview using a computer program (CIDI 2.1), working either on their own or with an assistant. They answer a range of questions about psychological disorders. Their responses to these are used to determine which questions from the pool they are subsequently asked and which are omitted. If sufficient symptoms are endorsed and they occur in certain patterns or clusters; a clinical diagnosis is made. All of this is carried out automatically by the computer program. The computer is objective and will not have preconceived ideas or beliefs about gender or ethnicity.
Issues affecting the validity of diagnosis in depression are gender. It has been found that rates of major depression are about twice as high in females as males and this finding holds good across cultures. Some people have suggested that this is a misleading statistic and reflects diagnostic practice rather than real gender differences. For example, it is more acceptable for women to admit to the kinds of symptoms that characterise depression than men, and women may feel more willing to go and ask for help. Culture is another factor because one key difference across cultures is the emphasis a particular society places on physical symptoms as a means of expressing mental problems. People from eastern cultures, in particular, often express their distress through physical symptoms. Kua et al reported that 72% of people in China who first presented with chest or abdominal pains or headaches were later fonud to have a mental health problem. One reason that people do not mention emotional symptoms when they first present for treatment is the stigma associated with emotional or mental weaknesses, especially in eastern cultures.
Finally; the effect of socio-cultural background means that people from social minorities seem to have a higher level of mental health probles than others. It is not clear whether this reflects greater genetic vulnerability, psycosocial factors associated with being part of a minority group or misdiagnosis. It could, for example, be the case that clinicians from a white middle class background misinterpret cultural differences in behaviour and expression as symptoms of mental disorder. If this is the case, it demonstrates how important it is for clinicians to take particular care in their assessment of people from different ethnic or social groups when diagnosing depression.
