validity of diagnosis

• concurrent validity?

  compares evidence with different diagnostic tests to see if they agree
• aetiological validity?

  when diagnosis reflects a known cause, could be due to damage of an area of the brain
• predictive validity?

  future cause of disorder is unknown, can be applied to a person so diagnosis can be checked against the outcome to see if it's valid
• what factor to do with giving different information impacts validity of diagnosis?

  patient factors, patient may not disclose all relevant information if they're embarrassed or because they don't remember all relevant details.
• what factor to do with the use of the classification system impacts the validity of diagnosis?

  clinician factors, implicit bias (pos/neg attitudes that a person holds at an unconscious level) can reduce validity since beliefs of a clinician can mean they arrive at an inaccurate diagnosis
• what factor to do with equipment used impacts the validity of diagnosis?

  classification system, Cochrane (1995) argues system leads practitioners to eurocentric bias.

  • Littlewood (1992), questions international validity of DSM-IV as assumptions about nuclear family life aren't applied to all cultures.
  • Jansson (1997), different classification systems focused on different features and symptoms in schiz which threatens validity.
• positive evidence for classification systems having an impact on validity?

  • Mason and colleagues (1997), diagnosis of schiz using ICD-10 = good predictive validity. found accurate diagnosis was done in 99 people, ICD was reasonably good at predicting disability 13 years later measured by global assessment of functioning questionnaire.
  • reflects social changes, DSM-5 acknowledges dementia is a growing problem and is neurocognitive disorder.
  • more accuracy = wars in Iraq and Afghanistan, provides more insight to PTSD and DSM-5 covers more symptoms like flashbacks.