88b - Classification and Diagnosis

Question 1

The DSM shifted to polythetic criteria in DSM-___

What does this mean?

Answer 1

The DSM 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

Illness

Answer 3

Person-based

Question 4

Disease

Answer 4

System and pathology-based

Question 5

Syndrome

Answer 5

Description-based

Question 6

Disorder

Answer 6

Comparison-based

Question 7

What two purposes does diagnosis serve?

Answer 7

Clinical utility (communication among clinicians and patients, treatment choice, epidemiology and documentation, classification)

Facilitation of research (communication among scientists, elucidation of pathology, clarification of terminology, developing and discovering treatments)

Question 8

Diagnostic reliability

Answer 8

When faced with the same patient, two psychiatrists should make the same diagnosis

Question 9

Diagnostic validity

Answer 9

Includes aspects of face validity, descriptive validity, predictive validity, and construct validity (i.e. sensitivity and specificity)

Question 10

Categorical diagnoses

Answer 10

May be defined by sets of rules and criteria (DSM) or a glossary of descriptions (ICD)

Question 11

Dimensional system

Answer 11

Uses ratings on a variety of dimensions or scales, often with normative comparisons and cutoff points

Question 12

Steps to achieving diagnostic validity for psychiatric disorders

Answer 12

Clinical description

Delimitation from other disorders

Follow-up study (including treatment response)

Family study

Laboratory studies

Question 13

Most psychiatric diagnosis is based on _____

Answer 13

Clinical syndromes

Question 14

The diagnosis classifications in psychiatry mostly use the term _____ rather than disease

Answer 14

Disorder

Question 15

Most psychiatric syndromes have non-psychiatric _____ differential diagnoses

Answer 15

Medical/physical/organic

Question 16

How would you respond to the criticism that psychiatric diagnoses are unreliable?

Answer 16

This is variable based on different diagnoses and other medical specialties have unreliable diagnoses, hence it is an epistemological problem widespread in clinical medicine, brain is very complex and thus harder to apply reductionistic science

Question 17

How does having an internally consistent reliable diagnostic system facilitate clinical research in psychiatry?

Answer 17

Having less heterogeneous study populations will decrease variability and increase statistical power