Research Methods

• Research Methods in Abnormal Psychology

  • Biological or Genetic Studies
  • Case Study/Single-Case Design
  • Group Level Designs
  • Cross-Sectional and Longitudinal Designs
  • Epidemiological Designs
• Biological or Genetic Studies

  • Neuroimaging, Genetic, Family/Twin/Adoption
• Group Level Designs


  • Correlational Methods
  • Controlled Group Designs (RCTs)
• Neuroimaging


  Using technology to gets a "picture" of how the brain is functioning
• Neuroimaging


  • Underlying assumption is that we can identify how a "normal" brain functions and then stable differences in "abnormal" brains would indicate where that problem originates
  • Types of scans: Electroencephalography (EEG), Computerized axial tomography (CAT), Magnetic Resonance Imaging (MRI), Functional Magnetic Resonance Imaging

  
• Biological Designs

  Uses study of genetic similarities to understand how behaviors, psychological distress, personality, etc. may be passed down through families
• Biological Designs


  • Family studies
  • Adoption studies
  • Twin studies
• Family studies


  • Is family member of someone with a disorder more likely to have the disorder than family member of someone without a disorder
  • Important first step in potentially identifying common genetic influence
• Adoption studies


  • Assume expression of some disorder common to family is genetically related since they were raised in different environment
• Twin studies


  • Study the differences between identical and fraternal twins
  • Allows understanding of environmental influence on behavior
  • Twin adoption studies - very rigorous design
• Case studies


  In depth assessment and description of behavior and/or treatment of an individual
• Single-Case design


  Experimental study conducted at the individual level
• Correlational Methods


  • Typically involves measuring multiple variables of interest and conducting some correlational analysis to examine their relationship
  • Does not allow for inferences of causation
• Controlled group designs

  Expose groups to different conditions that are manipulated by experimenter and then variables of interest are measured
• Independent variable (IV)


  The variable that is manipulated and assumed to have an effect or cause the change in another variable
• Dependent variable (DV)


  The variable that is measured as the outcome. It is not manipulated
• Randomized Controlled Design (RCT)


  Best version of controlled group design for inferring causality
• Randomized Controlled Design (RCT)


  • Participants are randomly assigned to groups
  • Participants and experimenters are blind to groups status, intervention status, etc. (double-blind study)
• Cross-sectional design


  Basically a snapshot in time, most studies use this approach
• Longitudinal design


  Measure same individuals over time, allows for a picture of developmental processes
• Epidemiological Designs

  Interested in the population as a whole, focuses on the occurrence of psychological disorders by time, place, and persons
• Key Epidemiological Concepts

  • Prevalence
  • Point prevalence
  • Lifetime prevalence
  • Incidence