Psychology Chapter on Abnormality Assessment

Defining Abnormality: Reliability and Validity

• Construct Validity: Crucial for ensuring operationalizations in a study accurately measure the intended constructs. It encompasses both reliability and validity aspects.
• Reliability: Consistency of measurement results. Three types exist:
  • Test-retest reliability: Consistency of scores across multiple test administrations, most relevant for stable constructs (e.g., intelligence, personality traits).
  • Interrater reliability: Consistency of ratings across different observers, essential for observational measures (e.g., aggressive behavior).
  • Internal reliability (internal consistency): Consistency of responses to multiple items within a self-report scale. Answers to related questions should align.

Empirical Validity Assessment

• Criterion validity: Assesses the association between a measure and a concrete behavioral outcome, particularly important for self-report measures to predict actual behaviors.
  • Example (Body Shape Questionnaire): Scores should correlate with eating disorder behaviors (vomiting, fasting, laxative/diuretic use).
• Known Groups Paradigm: Investigates if the measure distinguishes between pre-established groups known to differ on the trait being studied.
  • Example (Body Shape Questionnaire): Do scores differ between women with and without diagnosed eating disorders?
• Convergent validity: Measures should correlate with related measures. Scores on similar tests should show strong correlations.
  • Example (Body Shape Questionnaire): Scores should correlate with other self-report eating disorder measures.
• Discriminant validity: Measures should not correlate strongly with measures of unrelated constructs. Stronger correlations with similar constructs are expected.
  • Example (Body Shape Questionnaire): Scores should correlate more with other eating disorder measures than with depression measures.

DSM-5-TR

• Introduction (Assessment and Diagnosis): Assessment gathers information, and diagnosis labels clusters of symptoms. Diagnosis's benefits include facilitating communication, identifying causes and treatments, and guiding research. Potential drawbacks include stigma and oversimplification of the individual.
• DSM-5-TR: Diagnostic and Statistical Manual, current version reflecting a categorical classification approach. Specific criteria for disorders provide descriptions of features, research summaries, and associated symptoms (number of symptoms needed for a diagnosis).
• Categorical vs. Dimensional: Two approaches for classification. Categorical is used (presence/absence), while dimensional quantifies symptoms on a continuous dimension. DSM-5-TR is categorical.
• Criticisms: Growing numbers of diagnoses; comorbidity (presence of multiple disorders); and reliability and validity issues. Field trials yielded kappa values ranging from moderate to excellent but not as good as many medical diagnoses. Criterion validity is evaluated based on a measure's association with concrete behavioral patterns (functional disability in the case of mental disorders).

Clinical Interview

• Types:
  • Unstructured clinical interview: Clinician-driven, influenced by theoretical perspective, experience, and patient responses.
  • Structured clinical interview: Standardized format (e.g., SCID) with predetermined questions and branching logic, improves interrater reliability.
• Typical First Interview: Information gathering about presenting problems, comprehensive history (family, medical, educational, occupational), mental status exam, and informed consent regarding treatment.

Self-Report and Other Report Instruments

• Development and Scoring: Empirically validated instruments, scored in reference to norms.
• Examples:
  • MMPI-3: 335 true/false items, measuring multiple clinical symptoms, including validity scales.
  • NEO PI-R: 240 items measuring the Big Five personality traits.
  • SCL-90-R: 90 statements reflecting various symptoms with a 0-4 response format, measuring various aspects of psychological distress.
• Other Reports: Instruments like the Child Behavior Checklist (CBCL), gathering information from parents, teachers, and others.

Direct Observation and Self-Monitoring

• Direct Observation: Observing behavior in natural or laboratory settings. Key elements are antecedents, behavior, and consequences.
• Self-Monitoring: Individuals record their own thoughts, feelings, and behaviors (diaries, phones, etc.). Experience sampling (ecological momentary assessment) involves real-time data collection.
• Practical Considerations: The act of observation may alter the behavior being monitored.

Cognitive Assessment

• Intelligence Tests (e.g., WAIS): Assess current cognitive ability, often used to predict school performance, but are not the sole predictor. Also used to identify learning disabilities. Stereotype threat can affect results.
• Neuropsychological Testing: Detailed examination of cognitive abilities (memory, visuospatial perception, executive functioning), often based on the idea that different areas of the brain are involved in different aspects of cognition. Different batteries exist (Halstead-Reitan, Luria-Nebraska).

Neurobiological Assessment

• Brain Imaging (structural and functional): Structural imaging (CT, MRI) provides detailed images of brain structure. Functional imaging (fMRI, PET scan) allows for examining brain activity.
• Neurotransmitter Assessment: Postmortem studies examine the presence of neurotransmitters. Metabolite assays identify byproducts of neurotransmitter breakdown in body fluids, but may not reflect levels in relevant brain regions.
• Psychophysiological Assessment: Measures bodily responses (heart rate, EEG) that may correlate with psychological characteristics or events.