Psychophysiological Assessment

• Psychophysiological assessment examines the relationship between physical states (brain activity, heart rate) and psychological experiences (stress, emotion, arousal).

Psychophysiological Assessment Domains

• Electroencephalogram (EEG) measures brain wave activity.
• Heart rate and respiration measure cardiorespiratory activity, indicating the nervous system's response to psychological states.
• Electrodermal response and levels measure sweat gland activity.
• Electromyography (EMG) measures muscle tension.
• Plethysmograph measures sexual arousal.

Diagnosing Psychological Disorders

• Clinical assessment uses an idiographic approach, focusing on what is unique to the individual.
• Psychiatric diagnosis employs a nomothetic approach, applying general knowledge about people to specific cases.
• Both approaches are important for treatment planning and intervention.

Diagnostic Classification

• Classification involves developing categories based on shared attributes.
• Taxonomy is classification in a scientific context.
• Nosology is taxonomy in psychological/medical contexts, classifying diseases or psychological conditions.
• Nomenclature is the set of nosological labels, like "panic disorder."

Classification Systems

• The International Classification of Diseases and Health Related Problems (ICD-11) is published by the World Health Organization.
• The Diagnostic and Statistical Manual of Mental Disorders (DSM) is published by the American Psychiatric Association. The current version is DSM-5 (2013).

Approaches to Classification

• The classical/pure categorical approach involves yes/no decisions, viewing disorders as discrete categories with distinct criteria.
• The dimensional approach places symptoms or disorders on a continuum.
• The prototypical approach combines categorical and dimensional elements, requiring a minimum number of criteria to be met.

Purposes and Evolution of the DSM

• The DSM System aids communication, evaluates prognosis and need for treatment, and assists in planning treatment.
• DSM-I (1952) and DSM-II (1968) both relied on unproven theories and were unreliable.
• DSM-III (1980) through IV (2000) were atheoretical, focusing on observable symptoms and detailed criteria sets.
• DSM-5 (2013) emphasizes that many symptoms are not specific to a single disorder, and introduces dimensional measures to capture the severity of symptoms across disorders.

Research 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

• Research starts with a testable hypothesis.
• A research design is a method to test hypotheses.
• The independent variable is the variable that causes or influences behavior.
• The dependent variable is the behavior influenced by the independent variable.

Considerations in Research Design

• Internal validity refers to whether the independent variable produced the outcomes.
• External validity refers to the generalizability of the findings.
• Confounds are factors that might make results uninterpretable.
• Confounds can be minimized using control groups, random assignment, and analog models.

Relation Between Internal and External Validity

• Internal and external validity can be at odds, requiring researchers to prioritize one.
• Researchers often design multiple studies to balance these competing needs.

Statistical Methods and Clinical Meaningfulness

• Statistical methods determine whether observed patterns are real or due to chance.
• Statistical significance refers to whether results are due to chance.
• Clinical significance refers to whether results are clinically meaningful.
• Statistical significance does not imply clinical meaningfulness.
• Effect size should be evaluated. Effect size are statistical measures that tell the magnitude of effect but focuses less on sample size.

Studying Individual Cases: Case Study Method

• A case study involves extensive observation and detailed description of a single client.
• Case studies lack scientific rigor and suitable controls, leading to weak internal validity.

Research by Correlation

• Correlation is a statistical relation between two or more variables.
• Correlation does not equal causation.
• Correlations range from -1.0 to +1.0.
• In a perfect positive correlation (+1.0), as one variable increases, the other increases in exact proportion.
• In a perfect negative correlation (-1.0), as one variable increases, the other decreases in exact proportion.
• A correlation of 0.0 indicates no relationship between the variables.

Epidemiological Research

• Epidemiological research studies the patterns, causes, and effects of health and disease conditions in populations.
• Incidence is the number of new cases during a specified 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 is to find clues about the etiology (cause) of disorders.

Research by Experiment

• Used to study cause-and-effect relationships between variables.
• Experimental research involves manipulation of independent variables, random assignment, and an attempt to establish causal relations.

Group Experimental Designs

• Control groups are necessary to show that the independent variable is responsible for observed changes.
• A placebo group ensures the treatment effect is not due to the expectation of improvement.
• A double-blind design ensures both researchers and participants are unaware of group assignment.
• Comparative treatment designs compare different forms of treatment in similar persons, addressing treatment outcomes.
• Dismantling studies break a study into parts, to find the active components of treatment.

Single-Case Experimental Designs

• Single-case experimental designs involve the systematic study of individuals under a variety of conditions.
• Withdrawal designs manipulate the treatment (start, withdraw, restart) to observe changes in behavior.
• Multiple baseline designs introduce the intervention at different times across settings or behaviors without stopping and starting the treatment.

Genetic Research Strategies

• Behavioral genetics studies how genetic (genotype) and environmental factors interact to influence behavior (phenotype).
• Phenotype is an individual's observable characteristics or behavior.
• Genotype is an individual's genetic makeup.
• Family studies examine behavioral patterns in family members but cannot distinguish between environmental and genetic factors.
• Adoptee studies separate environmental from genetic contributions by comparing children to their biological and adoptive parents.
• Twin studies evaluate psychopathology in fraternal vs. identical twins.
• Genetic linkage and association studies locate the site of related genes.

Time-Based Research Strategies

• Cross-sectional designs compare different age groups at one time.
• Cohort effect: a confounding effect of age, is a major limitation of cross-sectional designs.
• Longitudinal designs follow one group over time, which can get closer to understanding causality
• Cross-Generalization Effect: may not be possible to generalize study effects to other groups whose experiences are quite different

Cross-Cultural Research

• Cross-cultural research studies abnormal behavior across cultures.
• Studing abnormal behaviour from various cultures can be informative and overcomes ethnocentric research.

The Nature of Programmatic Research

• Programmatic research is a series of studies contributing to a larger scientific inquiry.
• Scientific knowledge builds incrementally, and replication is vital.