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?