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					Diagnosing Mental Disorders

          January 29, 2010
   PSYC 2340: Abnormal Psychology
         Brett Deacon, Ph.D.
             Announcements

• Sona pretest is now online
• “On being sane in insane places” article review
  due on Monday
• Paper format: APA style not required, no
  references section, title page, or abstract
  needed
• No class next Wednesday and Friday
• I’m skipping the research methods lecture due
  to time constraints
            From Last Class

• “In the news” items
• Pseudoscience in abnormal psychology in
  action
     Diagnosing Mental Disorders

•   Chapter 3, pp. 85-95 ONLY
•   Section on diagnosing mental disorders
     Diagnosing Mental Disorders

• Diagnostic classification
  • Classification is central to all sciences
  • Develop categories based on shared attributes
  • Controversial when applied to human behavior
                 Classification

• Scientific classification strives to “carve nature at
  its joints”
• Seeks to identify “natural categories”
• Examples of natural categories of medical
  diseases: HIV, skin cancer, strep throat, hepatitis
• Of course, not all medical problems are natural
  categories
   • Hypertension, obesity, etc.
Classification and Natural Categories
     Classifying Mental Disorders

• Does nature have “joints” that represent different
  mental disorders?
• Do mental disorders represent natural
  categories?
Classification and Natural Categories:
    Analogy to Mental Disorders
     Classifying Psychopathology

• Categorical (classical) approach
• A person either has a disorder or does not
• Assumes each disorder has a clear underlying
  cause (most likely biological)
• Assumes each disorder is fundamentally unique
• Everybody with the disorder should meet all
  diagnostic criteria
• Medical vs. mental disorders
     Classifying Psychopathology

• Dimensional approach
• People have varying degrees of psychopathology
• Dimensions can overlap with each other
• Does not assume the presence of pathology
• What are the dimensions? How many are there?
  How to rate them? What to do with these ratings?
  What would third-party payers do with these
  ratings?
       Classifying Psychopathology

•   Prototypical approach
•   1. Identifies essential characteristics of a disorder
•   2. Allows for variations within the diagnosis
•   Diagnostic criteria include a number of
    symptoms, only some of which need to be met
• Combines elements of categorical and
    dimensional approach, but mostly categorical
• Exemplified in the DSM
  Classifying Major Depressive Disorder

• 5 or more symptoms must be met during a 2-week period
• Person must have at least 1 of these symptoms: (1) depressed
  mood most of the day, nearly every day, and (2) diminished
  interest or pleasure in all or almost all activities most of the day,
  nearly every day
• Other symptoms include:
   • Significant weight loss/gain or change in appetite
   • Insomnia or hypersomnia
   • Psychomotor agitation or retardation
   • Fatigue or loss of energy
   • Feelings of worthlessness or inappropriate guilt
   • Difficulty thinking or concentrating
   • Recurrent thoughts of death or suicidal ideation
    Classifying Antisocial Personality Disorder

•    3 or more of the following symptoms:
•    Repeatedly performing acts that are grounds for arrest
•    Deceitfulness (repeated lying, conning others, use of aliases)
•    Impulsivity or failure to plan ahead
•    Irritability and aggressiveness (repeated fights or assaults)
•    Reckless disregard for safety of self or others
•    Consistent irresponsibility (failure to hold a job or honor financial
     obligations)
• Lack of remorse (being indifferent to hurting others)
 Two Different Ways of Meeting Diagnostic
 Criteria for Antisocial Personality Disorder

• Person A: Frequently
  arrested for assault,
  cons others for personal
  pleasure, experiences
  no remorse when hurts
  others
• Person B: Recurrently
  arrested for possession
  or marijuana, difficulty
  keeping a job, often
  acts impulsively and
  displays poor judgment
Classifying Obsessive-Compulsive Disorder


• DSM-IV diagnostic criteria
   • Patient #1: hoarding
   • Patient #2: contamination fear
   • Patient #3: stabbing obsessions
   • Patient #4: checking
   • Patient #5: symmetry and arranging
Strep Throat: A Hypothetical Analogy

• Positive test for streptococcal (strep) bacteria
• Symptoms of streptococcal bacteria:
   • Severe sore throat
   • Pain or difficulty with swallowing
   • Fever over 101F
   • Swollen lymph nodes
   • Bright red throat or dark red spots on the roof
     of the mouth at the back near the throat
   • Swollen tonsils
Strep Throat: A Hypothetical Analogy

• What if we required 3 or more of the following symptoms
    to diagnose strep throat?:
•   Positive test for streptococcal bacteria
•   Severe sore throat
•   Pain or difficulty with swallowing
•   Fever over 101F
•   Swollen lymph nodes
•   Bright red throat or dark red spots on the roof of the mouth
    at the back near the throat
• Swollen tonsils
 Purposes and Evolution of the DSM
• Diagnostic and Statistical Manual of Mental
  Disorders (DSM); published by American
  Psychiatric Association
• DSM-I (1952) and DSM-II (1968)
  • Both relied on unproven theories and were
    unreliable
     Diagnostic Criteria for
“Phobic Reaction” in DSM-I (1952)
             The Modern DSM

• DSM-III (1980), DSM-III-R (1987), DSM-IV (1994)
  • Atheoretical, emphasizing clinical description
  • Detailed diagnostic criteria for each disorder
  • Checklist approach to diagnosis
  • Improved reliability for most disorders
  • Problems include low reliability for some
    disorders and reliance on committee
    consensus
              The DSM-IV (1994)
• Basic characteristics
  • Multiaxial approach to diagnosis
  • Five axes describing full clinical presentation
                   The DSM-IV
• Axis I – Most major disorders
• Axis II – Stable, enduring problems (e.g.,
  personality disorders, mental retardation)
• Axis III – Medical conditions related to abnormal
  behavior
• Axis IV – Psychosocial problems
• Axis V – Global clinician rating of adaptive
  functioning (Global Assessment of Functioning, or
  GAF)
               The Case of Jenny

Jenny, a 21-year-old nurse, has mild asthma. As an 8th
grader she watched her best friend die of a severe
asthma attack. Ever since then she has worried that
shortness of breath signifies an impending episode of
suffocation and death. When she has difficulty
breathing, she often experiences severe panic attacks
during which she is convinced she is dying. She was
referred to psychology after numerous ER visits,
unsuccessful medication trials, and relaxation training.
She frequently misses work because of her panic
symptoms and is in danger of being fired if she takes
any more sick days.
        Jenny’s DSM-IV Diagnosis

•   Axis I: Panic Disorder with Agoraphobia
•   Axis II: No diagnosis
•   Axis III: Asthma
•   Axis IV: Occupational problems
•   Axis V: GAF = 55 (Current)
     Diagnosing Mental Disorders

•   Primary role of mental health professionals
•   Scientifically questionable but practically
    indispensable in our current healthcare system
         Reliability and Diagnosis

• Reliability (interrater agreement). Affected by:
• Subjectivity of diagnostic criteria
• Patient report (accuracy, self-disclosure)
• Types of questions being asked by assessor
• Unstructured vs. structured interviews
   • Example: the MINI
         Validity and Diagnosis

• Validity (measures what its supposed to measure)
• In other words, does the diagnosis convey any
  special meaning or tell us anything useful?
  • Are the symptoms distinguishable from those of
    other disorders? (e.g., depression and GAD)
  • Is the diagnosis associated with a predictable
    cause, course, treatment prognosis, etc.?
       Advantages of Diagnosing

•   Enhances communication between
    professionals
•   Facilitates study of causes and treatments of
    specific disorders
•   Helps in treatment planning
•   Necessary for insurance reimbursement
•   DSM diagnoses have decent utility but
    questionable validity
     Disadvantages of Diagnosing
•   Adds little to our understanding of a problem
•   Suggests the presence of a disease state
•   Many diagnoses have poor reliability
•   Stigmatizes patients (?) and invites discrimination
•   What’s the difference between “feeling depressed” vs.
    having “major depressive disorder,” of being “anxious
    in social situations” vs. having “social anxiety
    disorder?”
•   “You’re feeling depressed because you’re suffering
    from major depressive disorder”

				
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posted:8/24/2011
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