Issues of classification & diagnosis

RELIABILITY
1. extent to which psychiatrists agree on same diagnoses when independently assessing patients.
  1. UK uses DSM others use ICD
    1. both have different criteria e.g. DSM recognises 5 sub types & ICD recognises 7
      1. diagnosis not consistent between different countries, people with same symptoms may be diagnosed normal in one part & schizophrenic in another.
        validity issues: SZ not understood well enough for accurate diagnosis
      2. Copeland: description patient. 69% US clinicians diagnosed them with SZ & 2% in UK.
        differences in what people expect symptoms to be like, creating issues in diagnosis as behaviour in one country is seen as normal in the context of that culture but a symptom in another.
2. Consequences for patients: stigmatised & mistreated raising ethical concerns.
  1. label will stay with them & affect employment, social interaction & how they are perceived as others are usually suspicious of such labels due to extreme media interpretations of SZ's as violent & insane
    1. no physical cause that can be conclusively measured & patients must self report symptoms, not always accurately, maybe due to their disorder, hindering reliability.
      1. objective diagnosis is difficult.
        interpretation of symptoms is subjective, individual's ability in diagnosis is very important but may vary between health professionals.
        skill, experience & knowledge further affect reliable diagnosis
Whaley: inter-rater reliability between health professionals as low as 0.11. Shows when independently assessing patients, diagnosis was rarely consistent between them meaning DSM is unreliable in accurately & consistently diagnosing SZ.
1. states only one symptoms required if delusions are 'bizzare'
2. Study: 50 psychiatrists asked to distinguish between bizzare & non-bizzare. Only 0.40 inter-rater reliability correlations. Lacks sufficient reliability to distinguish between SZ & non-SZ symptoms.
  1. Rosanhan: gives further support for unreliability. normal people went to psychiatric hospitals saying they heard voices. all diagnosed as SZ. During their stay no staff recognised they were actually normal, highlighting unreliability.
VALIDITY
1. if practitioners can't conclusively agree who has SZ or not, raises question of what it actually is & whether understanding is sufficient.
  1. comprehensive review of symptoms, causes & outcomes of SZ concluded SZ was not useful scientific theory.
  2. Schneider developed first rank symptoms e.g. delusions of control, thought broadcast & auditory hallucinations which would distinguish SZ from other disorders.
    1. believed would make diagnosis more valid & reliable. But overlap with disorders like depression & bipolar.
      1. pointed out that people with dissociative identity disorder actually have more SZ symptoms than diagnosed SZ's.
        comorbidity issues as symptoms may fit in with SZ but may be due to other illnesses resembling it, making diagnosis unreliable & treatment difficult.
no evidence to suggest SZ's share same outcomes.
1. outcomes vary from 20% recovering to normal functioning, 10% achieving lasting improvement, 30% showing improvement with relapses.
  1. diagnosis shows little predictive validity as some people recover while others don't.

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Issues of classification & diagnosis

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	Created by diana.m1629 about 10 years ago