Psychopathology

• No absolute definition of what is considered pathological or abnormal
• psychopathological decision: assessments and treatments
• 3 ways to define psychopathology: 1. statistical deviation 2. subjective distress 3. Personal dysfuntion
• Wakefield = Harmful dysfunction
• Wakefield's definition of psychopathology: 1. scientific component(dysfunction in brain process involved in thinking and feeling) 2. social component (behavior judged as causing harm in one's own sociocultural context)
• Kraepelin adopted medical model and applied to mental health
• Kraepelin assumes that mental illnesses are categorical, discrete, measurable entities
• medical model assumptions: 1. different disorders are discrete, separate categories 2. mental illness is discontinuous with normal behavior
• Categorical systems are discrete. It has the presence or absence of disorder. This is what the DSM currently has.
• Dimensional is continuous. This is a rank on continuous quantitative dimension and the data better support this view
• There are 5 purposes of the DSM classification system.
• purposes of the DSM classification system: 1. facilitate communication among mental health professionals 2. allow for treatment and intervention recommendations 3. promote research about disorders and treatment 4. allocate resources and services 5. provides a sense of understanding to the individual
• Inter-rater reliability looks at rate of agreement between clinicians
• Cohen's Kappa statistic: varies between 1 (perfect agreement) and -1 (less disagreement than expected by chance alone)
• Internal consistency refers to the homogeneity of the test
• On a questionnaire, a high alpha indicates a consistent pattern across items
• 2 individuals with the same diagnosis can share very few or even no symptoms in common
• A reliable classification system should put people with the same symptoms in the same category, and different symptoms in a different category.
• Item relevance measures important aspects of the construct
• Validity evidence based on test content: item relevance
• Validity evidence based on test content : item coverage
• item coverage measures the whole construct
• item overlap is when items are similar to other tests that measure the same thing
• construct validity refers to how well an instrument measures what it claims to be measuring
• content validity is whether or not all relevant information has been included in the assessment tool
• content validity is the extent to which all relevant areas have been covered by the test
• face validity is whether or not the test looks like it's supposed to measure
• face validity is whether or not the assessment looks like it's assessing what it says it does
• criterion-related validity is whether or not the results from one test can predict performance on another test
• criterion-related validity is the relationship between scores from one test and another test, behavioral criterion, or performance standard
• face validity is the degree to which the test appears to assess what it purports to measure
• The validity evidence is based on patterns of associations: does the measure correlate with or predict other theoretically-relevant constructs and/or criteria?
• Validity evidence based on patterns of associations: 1. what causes the disorder 2. what outcomes/consequences does the disorder predict 3. What treatment improves the disorder
• Sensitivity: can the test detect the disorder when it is present
• Specificity: can the test detetc the absence of the disorder wjen it is absent
• Mental illness is discontinuous with normal behavior
• Validity evidence based on internal structure: mental disorders are discrete, categorical entities
• A major threat to validity evidence based on internal structure: very high degree of comorbidity among mental disorders
• comorbidity: to the presence of two or more disorders in the same person
• Tom Achenbah used factor Analysis to understand the underlying structure of mental disorders