Issues in Diagnosis + Classification

• Good Reliability - Strength

  - inter-rater reliability -same diagnosis for an individual

  - test-retest - same diagnosis on two occasions

  - Osorio et al - excellent reliability for the diagnosis with DSM-5

  - inter-rater reliability - +9.7, test-retest - +9.2

  - consistent
• Low Validity - Weakness


  - assess what we are trying to assess?

  - low criterion validity

  - Cheniaux et al - two psychiatrists, assess 100 clients with DSM-4 and ICD-10

  -68 diagnosed with SZ under ICD

  - 39 under DSM
• Co-Morbidity - Limitation


  - co-morbidity with other conditions

  - if they occur together, questions the validity of their diagnosis

  - may be 1 single condition

  - Buckley et al - 1/2 with SZ had depression or substance abuse

  - problem for classification

  - SZ may not be a distinct condition
• Gender Bias In Diagnosis - Limitation

  - 1980's - men diagnosed more commonly

  - Fischer and Buchanan - ratio of 1.4:1

  - women are under diagnosed

  - Cotton et al - closer relationships = support = functioning better

  - women may not receive treatments and benefits
• Culture Bias In Diagnosis - Limitation

  - symptoms have different meaning in different cultures (hearing voices)

  - Haiti, voices = ancestors

  - Pinto and Jones - Afro-Carribean Brits, 9x more likely to get diagnosed than white people

  - culture bias by psychiatrists from a different culture

  - Escobar - over interpretation of symptoms in Black Brits

  - discrimination
• Symptom Overlap - Limitation

  - overlap with conditions like bipolar

  - classification - SZ and bipolar may be one condition

  - classification and diagnosis are flawed