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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
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Diagnosing Mental DisordersJanuary 29, 2010PSYC 2340: Abnormal PsychologyBrett 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.
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
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”