chapter three clinical research, assessment, and diagnosis in abnormal psychology

Chapter Three

Clinical Research, Assessment, and Diagnosis in Abnormal

Psychology

Clinical Research, Assessment, and Diagnosis in Abnormal Psychology

• Psychopathology:– Study of mental or behavioral disorders

• Etiology:– Cause or origin of a disorder

The Scientific Method in Clinical Research

• Replication: – Results repeated in multiple studies to reduce the

chance of findings due to experimenter bias, methodological flaws, or sampling errors

• Scientific method: – Provides systematic collection of data, controlled

observation, and the testing of hypotheses

• Hypothesis: – Conjectural statement that usually describes a

relationship between two variables

The Case Study

• Case study: – Intensive study of one individual that relies on

clinical data, such as observations, psychological tests, and historical and biographical information

– Provides detailed information about development and psychopathology in a specific individual

– Helps to develop a strong therapeutic relationship

The Case Study (cont’d.)

• Limitations:– Findings cannot be generalized to others– Data reflects theoretical perspective or bias of

investigator– Cannot be used to demonstrate cause and effect

relationships

Correlational Studies

• Statistical analysis preformed to determine the relationship between variables

• Positive correlation: – Increase in one variable accompanied by increase

in the other• Negative correlation:

– Increase in one variable accompanied by decrease in the other

Correlational Studies (cont’d.)

Figure 3-1 Possible Correlation Between Two Variables The more closely the data points approximate a straight line, the greater the magnitude of the correlation coefficient r. The slope

of the regression line rising from left to right in example (a) indicates a perfect positive correlation between two variables, whereas example (b) reveals a perfect negative correlation. Example (c) shows a lower positive correlation. Example (d shows no correlation whatsoever.

Correlational Studies (cont’d.)

• Allow for the study of variable that cannot be controlled

• Correlations indicate the degree to which two variables are related, not the reason for the relationship– Cannot determine cause and effect– Factors may be influenced by an additional

variable

Experiments

• Experiment: – Perhaps best tool for testing cause and effect

relationships because variables can be manipulated

• In its simplest form, an experiment involves:– Experimental hypothesis– Independent variable– Dependent variable

Experiments (cont’d.)

• Experimental hypothesis: – Prediction concerning how an independent

variable will affect dependent variable

• Independent variable: – (Possible cause) experimenter manipulates to

determine effect on dependent variable

• Dependent variable: – Expected to change when an independent

variable is manipulated

Experiments (cont’d.)

• Experimental group: – Subjected to independent variable– Subjective: taking place in person’s own mind

• Control group: – Similar in every way to experimental group except

for exposure to independent variable

• Placebo control group: – Induces expectancy without actual treatment (no

manipulation at all)

Experiments (cont’d.)

• Additional controls in clinical research:– Blind design:

• Those helping with the study are not aware of research• Reduces impact of experimenter expectations

– Double-blind design: • Neither participants nor experimenters are aware of

experimental conditions• Reduces impact of experimenter and participant

expectations

– Researchers attempt to increase degree of blindness and decrease expectancy effects

Experiments (cont’d.)

• Shortcomings:– Effectiveness of blind designs depends on

participants being truly “blind”– Some variables cannot be manipulated– Questions regarding generalizability of results

Analogue Studies

• Replicate or simulate real-life situations under controlled conditions

• Used when not possible to control all variables in real-life situations

• Advantage: allows study of phenomenon using experimental designs that are not possible with correlation studies

Field Studies

• Behaviors and events are observed and recorded in their natural environment

• Sometimes used to examine catastrophic events or personal crises

• Offer a more realistic investigative environment

Field Studies (cont’d.)

• Limitations: – Cannot be used to determine cause and effect

relationships– Many factors affecting real-life situations makes it

impossible to control and distinguish all possible variables (difficult to interpret)

– Observer can never be sure their presence did not influence interactions they observed

Biological Research Strategies

• Genetics and epigenetics: – Focus on influence of specific genes in

development of psychopathology– Epigenetics:

• Shedding light on how the environment influences or programs gene expression

• Genetic linkage studies: – Attempts to determine whether a disorder follows

a genetic pattern

Biological Research Strategies (cont’d.)

• Endophenotypes:– Measurable characteristics (neurochemical,

cognitive, etc.) that can give clues regarding specific genes involved in a disorder

– Characteristics must be heritable• Seen in family members who do not have the disorder• Occur more frequently in affected families than in the

general population

Biological Research Strategies (cont’d.)

• Epidemiological survey research: – Study of the rate and distribution of mental

disorders in the population– Prevalence:

• Percentage of individuals in targeted population with a particular disorder during a specific period of time

– Incidence: • Number of new cases of a disorder that appear in an

identified population within a specific period of time

– Important in analyzing possible causal factors

Assessment of Abnormal Behavior

• Therapists collect and organize information about a person’s current condition and past history to better understand symptoms and mental state

• Psychodiagnosis:– Description of an individual's psychological state

and inferences about possible causes of distress

Reliability and Validity

• Reliability: – Degree to which a procedure yields the same

results repeatedly under the same circumstances• Test-retest reliability:

– Same results when given at two different points in time

• Internal consistency: – Various parts of measure yield similar or consistent results

• Inter-rater reliability: – Consistency of responses when different raters administer

measure

Reliability and Validity (cont’d.)

• Validity: – Degree to which an instrument measures what it

was developed to measure• Predictive validity:

– Is measure able to predict how a person will behave, respond, or perform

• Construct validity:– Is measure related to phenomena related to measure

Reliability and Validity (cont’d.)

• Standardization: – Crucial to reliability and validity of tests– Administration of all testing requires that

common rules and procedures are followed– Requires a comparison group to which an

individual’s test performance can be compared

Assessing Abnormal Behavior

• Assessment: – Process of gathering information and drawing

conclusions about an individual’s traits, skills, abilities, emotional functioning, and psychological problems of an individual

• Principal means of assessment:– Observations– Interviews– Psychological tests and inventories– Neurological tests

Assessing Abnormal Behavior (cont’d.)

• Observations:– Controlled (analogue) observations:

• Made in laboratory, clinic, or other contrived setting

– Naturalistic observations: • Made in natural setting (schoolroom, office, hospital

ward, home)

– Can be highly structured and specific or less formal

– Observe appearance and behavior

Assessing Abnormal Behavior (cont’d.)

• Interviews:– Observe client and collect data about the person’s

life history, current situation, and personality– Analyze:

• Verbal behavior• Nonverbal behavior• Content• Process of communication

Assessing Abnormal Behavior (cont’d.)

• Interviews:– Vary in degree of structure and formality with

which they are conducted – Mental status examination:

• Evaluate individual’s cognitive, psychological, and behavioral functioning

• Useful diagnostic tool• Fallible and subjective

Assessing Abnormal Behavior (cont’d.)

• Psychological tests and inventories:– Standardized instruments used to assess:

• Personality • Maladaptive behavior • Social skills • Intellectual abilities • Vocational interests • Cognitive impairment

Assessing Abnormal Behavior (cont’d.)

• Projective personality tests:– Test taker is presented with ambiguous stimuli

and is asked to respond to them in some way• Rorschach Technique• Thematic Apperception Test (TAT)• Sentence-completion test• Draw-a-person test

– Limited support for interpretations of TAT, Rorschach, and draw-a-person test

– Questionable cultural relevance

Assessing Abnormal Behavior (cont’d.)

• Self-report inventories:– Test taker answers specific written questions or

selects specific responses from a list of alternatives

– Minnesota Multiphasic Personality Inventory (MMPI and MMPI-2)

• Most widely used

– Beck Depression Inventory (BDI)

Assessing Abnormal Behavior (cont’d.)

Figure 3-2 The 10 MMPI-2 Clinical Scales and Some MMPI-2 Items Shown here are the MMPI-2 clinical scales and a few of the items that appear on them. As an example, answering “no” or “false” (rather than “yes” or “true”) to the item “I have a good appetite”

would result in a higher scale score for hypochondriasis, depression, and hysteria. Source: Adapted from Dahlstrom & Welsch, (1965). These items from the original MMPI remain unchanged in the MMPI-2.

Assessing Abnormal Behavior (cont’d.)

• Limitations of self-report inventories:– Fixed number of choices hinder accurate

presentation – Unique response sets may distort results– Interpretations of responses may be inaccurate if

culture context is not addressed– Cultural factors may shape way a trait or

characteristic is viewed

Assessing Abnormal Behavior (cont’d.)

• Intelligence tests:– Obtain intelligence quotient (IQ), or estimate of

current level of cognitive functioning – Wechsler scales– Stanford-Binet scales

Assessing Abnormal Behavior (cont’d.)

Table 3-2 Items Similar to Those for the Wechsler Adult Intelligence Scale-IV

Assessing Abnormal Behavior (cont’d.)

• Criticisms of intelligence tests:– Popularized as measuring innate intelligence, but

actually reflect cultural and social factors– Predictive validity – Inadequacies of current conceptions of IQ tests

• Misses multidimensional attributes of intelligence

Assessing Abnormal Behavior (cont’d.)

ABC Video: Measure of IQ Can IQ tests accurately measure how smart you are or determine your future success? The theory of multiple intelligence may explain why

traditional IQ tests may not always be an accurate measure of intelligence.

Assessing Abnormal Behavior (cont’d.)

• Tests for cognitive impairment:– Detect and assess cognitive impairment

• Bender-Gestalt Test• Halstead-Reitan Neuropsychological Test Battery

– Are widely used and have been found to be effective and valid in evaluating cognitive impairment due to brain damage

Assessing Abnormal Behavior (cont’d.)

Figure 3-4 The Nine Bender Designs The figures presented to participants are shown on the left. The distorted figures drawn by an individual with suspected brain damage are shown on

the right.Source: L. Bender, (1938)

Assessing Abnormal Behavior (cont’d.)

• Neurological tests:– Electroencephalograph (EEG)– Computerized axial tomography (CT) scan– Magnetic resonance imaging (MRI)– Positron emission tomography (PET) scan– Increase diagnostic accuracy and understanding

when coupled with psychological tests

Assessing Abnormal Behavior (cont’d.)

ABC Video: MRI as a Lie Detector Learn about the experimental use of Functional Magnetic Resonance Imaging to map activity in the region of the brain used for deception.

Diagnosis and Classification of Abnormal Behavior

• Classification system: – Provides distinct categories, indicators, and

diagnostic names for particular patterns of behavior, thought processes, and emotional disturbances

– Means of diagnosing disorders – Facilitates communication between mental health

professionals– Forms foundation for research

Diagnostic and Statistical Manual of Mental Disorders (DSM)

• Widely used classification system– Lists all officially designated mental disorders and

the characteristics or symptoms needed to confirm diagnosis

– Traditionally a categorical system but most recently proposed as a dimensional model

Diagnostic and Statistical Manual of Mental Disorders (cont’d.)

• DSM-5:– Dimensional system:

• Disorders lie on a continuum with “normality” at one end

– Includes culturally focused interview– Comorbidity:

• The co-occurrence of different disorders

Evaluation of the DSM Classification System

• Positive aspects of DSM-5:– Moves away from a categorical system and

towards a dimensional system– Developed to increase reliability and validity

• Criticisms of DSM-5:– Lowers diagnostic thresholds – Inclusion of questionable “new disorders”– Cultural concerns– Focus on resilience:

• Should strengths be assessed?