Classification

Question 1

What is classification?

Answer 1

Classification is the act of constructing groups (classes) and assigning things to these classes on the basis of their shared attributes

Question 2

How have mental illnesses historically been classified?

Answer 2

Mental disorders have historically been classified on the basis of shared patterns of symptoms

Question 3

Kraepelin (1856 – 1926) contribution?

Answer 3

Published the Compendium der Psychiatrie in 1883
(major revisions in 1904 and 1907)
 Defined 15 categories of mental disorders based on
common patterns of symptoms
 Most famous for the “Krapelinian dichotomy”:
dementia praecox (schizophrenia) vs manic
depression

• there is a fair assumption that similar disease processes will produce identical symptom pictures, identical pathological anatomy, and an identical etiology” (Kraepelin, 1907)

Question 4

Kraeplin thought that similar disease processes will produce…

Answer 4

identical symptom pictures, identical pathological anatomy, and an identical etiology” (Kraepelin, 1907)

Question 5

Why do we classify mental disorders? (Advantages)

Answer 5

 Common vocabulary – reduces complex information on symptom
profiles to better enable communication between clinicians and
researchers
 Provides a guide for treatment and prognosis
 Third party considerations – e.g., insurance companies require a
diagnosis before paying for treatment; some early-intervention
programs require a diagnosis prior to admittance
 Maybe it’s valid? Symptoms do tend to cluster together

Question 6

Two basic approaches of classify mental disorders?

Answer 6

(1) Categorical approach 
 yes
or no?
 Classical vs Prototypical
 DSM primarily employs a prototypical categorical approach 
(2) Dimensional approach - how much?

Question 7

DSM employs what approach of classification?

Answer 7

DSM primarily employs a prototypical categorical approach

Question 8

Basic structure of DSM 5?

Answer 8

Diagnostic Categories
 22 diagnostic categories in DSM-5
- e.g. Anxiety Disorders, OCD Disorders, Depressive Disorders

Disorders
 E.g., The ‘Anxiety Disorders’ category consists of: Specific Phobia, SAD, GAD, etc.

Subtypes
 E.g., Specific phobias: animal, natural environment, blood-injury-injection, etc
 Changed over time
 5 schizophrenia subtypes in DSM-IV-TR (paranoid,
disorganized, catatonic, undifferentiated and residual), removed in DSM-5

Question 9

Limitations of a categorical approach?

Answer 9

 The line between normality and abnormality is sometimes blurry, or even arbitrary
 People can be diagnosed with the same disorder despite having few – in any! – symptoms in common

Question 10

Schizoaffective disorder is when….

Answer 10

Patient has features of both schizophrenia (psychosis, negative symptoms, cognitive impairment) and
bipolar disorder (Characterized by mood disturbances), but does not strictly meet diagnostic criteria for either

Question 11

What is Minnesota Multiphasic Personality Inventory (MMPI)?

Answer 11

 First developed in 1943, updated in 1989
 10 ‘dimensions’ of psychopathology along which
people differ
 e.g., hypochondriasis (HS), depression (D),
paranoia (PA), psychasthenia (PT), hypomania
(MA), psychopathic deviate (PD) etc.
 Individual’s score on each dimension is compared
to population norms

Question 12

Limitations of the dimensional approach?

Answer 12

 No common vocabulary
 Unwieldly
 Implications for treatment?
 E.g., what’s the best way to treat someone who is high on hypochondriasis, but low on depression but high on social introversion, but low on paranoia, etc….
 Does a consistent pattern define a diagnostic category?

Question 13

Advantages of categorical approach

Answer 13

 Common vocabulary, aids communication
 Provides a guide for treatment and prognosis
 Third-party considerations

Question 14

Advantages of dimensional approach

Answer 14

 Closer to reality?

 Doesn’t require arbitrary distinctions between normality and abnormality

Question 15

What is the Research Domain Criteria (RDoC) Project?

Answer 15

• Tom Insel

- Aims to “develop, for research purposes, new ways of classifying mental disorders”

Question 16

What are the assumptions of RDoC?

Answer 16

 Mental disorders are biological disorders involving brain circuits that implicate specific domains of cognition, emotion, or behavior
 Mapping the cognitive, circuit, and genetic aspects of mental disorders will yield new and better targets for treatment.
 A diagnostic approach based on the biology as well as the symptoms must not be
constrained by the current DSM categories