4.10.09

Diagnostic reliability



In the film, Mr Jones, Richard Gere plays a character with a mental health problem. He is admitted to a psychiatric unit after climbing on to the roof of a house and claiming he can fly. The attending psychiatrist conducts an initial clinical assessment and identifies the following signs and symptoms: highly agitated, delusional, auditory hallucinations. The initial diagnosis based on these signs and symptoms is paranoid schizophrenia and he is prescribed 10 mg of Haloperidol. So far, so good. 

But, one of the major problems with the classification and diagnosis of mental disorders is that different types of mental disorder share similar symptoms:

"I think he was misdiagnosed - he was psychotic but not schizophrenic, he was expansive, innapropriate, intrusive, euphoric, I think he is manic".

Accurate and reliable diagnosis is important for the patient, it determines how they are treated and with what drugs: antidepressants for depression, major tranquillizers for schizophrenia. Get it wrong and the person can be given drugs that make their mental disorder worse. 

Mood disorders are the general class of a range of different affective disorders. Major or unipolar depression and bipolar depression are very different types of mood disorder. Unipolar disorder also has a number of distinct diagnostic sub categories: Melancholic depression, Catatonic depression, Post-partum depression, and A-typical depression. These may all have different causes and require different treatment.

This is especially important for bipolar affective disorder. Diagnose major depression and treat with antidepressants and you may make their condition worse: antidepressants may destabilise their mood rather than stabilise it. Lithium carbonate is the most common and effective form of treatment for someone with bipolar affective disorder.

Diagnosis is not always accurate and different psychiatrists may diagnose very different mental disorders for the same patient. Lipton and Simon conducted a study of the reliability of psychiatric diagnosis in 1985. They re-evaluated  the diagnosis of patients by psychiatrists in a psychiatric hospital in New York. Out of 89 patients that were diagnosed as schizophrenic by the hospital psychiatrists the inspection team only diagnosed 16 as schizophrenic. Only 15 patients in the original sample were diagnosed with depression by the hospital psychiatrists but the inspection team identified 50 patients with depression and changed their diagnosis.

When I worked in mental health I would often look through a patients notes, their medical history and history of admittance to a psychiatric unit. Often I would find more than one diagnosis depending on the consulting psychiatrist: schizophrenia would give way to schizophreniform disorder to borderline personality disorder to just a demanding pain in the........

Link to part 3 of Mr Jones

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