Psychophysiological Assessment Methods

• Psychophysiological assessment methods evaluate brain structure, function, and nervous system activity.

Psychophysiological Assessment Domains

• Electroencephalogram (EEG) measures brain wave activity.
• Heart rate and respiration assess cardiorespiratory activity.
• Electrodermal response and levels indicate sweat gland activity.
• Electromyography (EMG) measures muscle tension.
• Plethysmography assesses sexual arousal.

Clinical Assessment vs. Psychiatric Diagnosis

• Assessment uses an idiographic approach, focusing on unique individual characteristics like personality, family background, and culture.
• Diagnosis uses a nomothetic approach, applying general knowledge of problems to see if specific issues fit a broader class.
• Both assessment and diagnosis significantly aid in treatment planning and intervention strategies.

Diagnostic Classification

• Classification underpins all sciences, which facilitates the development of shared attribute categories.
• Taxonomy is the classification in a scientific context.
• Nosology is the taxonomy used in psychological/medical contexts.
• Nomenclature is the nosological labels, such as panic disorder.

Classification Systems

• Two widely used systems include:
  • International Classification of Diseases (ICD), published by the WHO.
  • Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the APA.

Nature and Forms of Classification Systems

• Classical (or pure) categorical approach:
  • Uses yes/no decisions based on categories.
  • Each disorder is viewed as fundamentally different, with a clear underlying cause.
  • Requires individuals to meet all criteria for classification.
  • Useful in medicine, but often seen as inappropriate for psychological disorders' complexity.
• Dimensional approach:
  • Classifies symptoms or disorders along a continuum like 0 to 100.
  • An individual might be mildly depressed (60) and moderately anxious (70).
  • Creates a profile to represent a person’s overall functioning.
  • Lacks agreement on the number or types of dimensions needed.
• Prototypical approach:
  • Combines classical and dimensional approaches.
  • Uses categorical yes/no decisions but doesn't require fitting every symptom.
  • Requires meeting a minimal number of prototypical criteria (e.g., 5 of 9 depression symptoms).

Purposes and Evolution of the DSM

• Aiding effective communication among professionals.
• Evaluating prognosis and the necessity for treatment.
• Planning and executing treatment strategies.
• DSM-I (1952) and DSM-II (1968) relied on unproven theories and lacked reliability.
• DSM-III (1980) through DSM-IV (2000):
  • Emphasized clinical description instead of underlying etiology.
  • Used detailed criterion sets for disorders.
  • Focused on reliability (inter-rater; test-retest), but questions arose about validity.

Science and Abnormal Behavior

• Key questions in psychopathology:
  • What problems cause distress or impair functioning?
  • Why do people behave in unusual ways?
  • How can we help people behave in more adaptive ways?

Basic Components of Research

• Starts with a testable hypothesis or "educated guess" which can be either rejected or accepted.
• Research design is the method used to test the hypothesis.
• The independent variable is what causes or influences behavior.
• The dependent variable is the behavior that is influenced.

Considerations in Research Design

• Balancing internal vs. external validity is crucial.
• Internal validity determines whether the independent variable produced the outcomes and if the results can be trusted.
• External validity assesses if the findings are generalizable across different settings, locations, samples, or problems.
• Increase internal validity by minimizing confounds, factors that might make results uninterpretable.
• Control groups include individuals not exposed to the independent variable but are otherwise similar to the experimental group.
• Random assignment procedures ensure individuals are assigned randomly to experimental or control groups to avoid systematic bias.
• Analog models study related phenomena in controlled laboratory conditions.

Relationship Between Internal and External Validity

• The relationship between internal and external validity can be conflicting.
• Prioritizing one over the other is often necessary.
• Though controlling confounds enhances internal validity, it may limit the generalizability to real-world scenarios.
• Balancing these needs often requires designing multiple studies.

Statistical Methods and Clinical Meaningfulness

• Statistical methods protect against biases in evaluating data.
• Measures whether results are due to chance.
• Considerations include effect size, level of significance, and sample size.
• Clinical significance:
  • Asks if the results are clinically meaningful.
  • Statistical significance doesn't ensure clinical relevance.
  • Balancing both involves evaluating effect size.

Studying Individual Cases: Case Study Method

• Case studies involve extensive observation and detailed description of a client.
• Serve as foundations for early developments in psychopathology.
• Limitations include:
  • Lacking scientific rigor and suitable controls.
  • Typically weak internal validity.
  • Often entailing numerous confounds.
  • Having findings unique to the individual.
  • Inferences are drawn from the researcher and have no tangible metrics.

Research by Correlation

• Correlation measures the statistical relation between two or more variables without manipulating an independent variable.
• Correlation does not equal causation due to the problem of directionality.
• The range is from -1.0 to +1.0.
• Uses include situations where random assignment and manipulation of an independent variable are not possible.

Epidemiological Research

• Examines incidence, prevalence, and course of disorders to find clues about disorders.
  • Looks at the number of new cases during a specific time.
  • Prevalence is the number of people with a disorder at any given time.
• Distribution refers to how common a disorder is in certain populations.
• The goal includes identifying factors associated with the frequency of disorders and finding clues about their etiology.