96b - Classification and Diagnosis

Question 1

The DMS shifted to polythetic criteria in DSM-___

What does this mean?

Answer 1

The DMS shifted to polythetic criteria in DSM- III

• Introduced “total number” and “cutoff number” of symptoms/criteria
• The DSM-III is also known as the “atheoretical” period
  
  • More description of symptoms
  • Less focus on meaning behind symptoms
    (@Freud was most likely unhappy)

Question 2

What is the difference between reliability and validity in psychiatric diagnosis?

Answer 2

• Reliability
  
  • Different clinicians come to the same diagnosis for the same patient
  • The same patient presenting at different times gets the same diagnosis
• Validity
  
  • Face validity - the diagnosis is right (?)
  • Predicted validity - can predict course, consequences of progression
  • Construct validity - sensitivity and specificity
  • Validity is hard to achieve in psychiatric diagnoses due to complexity of human behavior and cognition

Reliability is necessary but not sufficient for validity

Question 3

What are the steps to achieving diagnostic validity?

Answer 3

1. Clinical description
2. Delineation from other disorders
3. Follow-up study (and treatment response)
4. Family study
5. Laboratory study