Objective:
• Scientific Method
• Threats to findings
• Adequacy of findings
• Research strategies/clinical trials
• Statistical vs Clinical Significance
• Range of primary foci o Description (DSM) o Causation (psychopathology) o Intervention/outcome (one of primary reasons for the study of abnormal psychology)
Historical Perspectives revisited: Integrative models
Diathesis-Stress
• Basic argument: we are all born with a physiological vulnerability to the development and expression of mental health disorders
• Multiple genetic factors
• We have to a greater or lesser extent, that genetic vulnerability
• Person A vs B vs C
• Person A may have a small amount of genetic vulnerability, B has more and C has the most
• Each person must experience a certain amount of “stress” before they will express a mental health disorder
• Stress is psychosocial (or environmental) in nature; stress is not constant it’s fluid, ebbs and flows
• Risk factor is biological in nature
• Diathesis may be related to interpersonal factors; or stress is related to biological factors
• Additive model; certain amount of vulnerability and stress then does it reach the threshold for mental health disorder or not
• Risk of expression influenced by stress
• Some pathology factor that we can identify that produces this form of deviance dysfunction; not of the models that he introduce can do an adequate job of explaining all of the abnormal pathologies; better to take an integrative look; the most basic of the integrative models is the diathesis-stress model
Reciprocal Gene-Environment
• More dynamic process than diathesis
• Assumes that the traits associated with our genetic endowment that may lead us to experience stress
• People who like risk will seek activities that expose them to risky situations which would expose them to more environmental stressful events.
• We still have an additive process, but it’s our traits that make us more or less likely to expose ourselves to stress
Introduction: Research … Scientific method
Identify / define problem of interest
Gather background information
Develop strategy for testing hypothesis
Conduct study, review findings
Refine hypothesis and continue process
Range of research objectives
Description
Causation
Intervention / treatment outcome
Managing “random error”
Threats to findings
• Imprecision of measures of interest o Ex. Using a ruler to measure barometric pressure o Use a measure appropriate to the measure of thing of interest
• Error
Validity revisited
Internal Validity (IV)
• The independent variable causing the dependent variable to change
• Can enhance IV by random assignment of groups, use of control groups (ensure that a group of subjects is exposed to everything except the active ingredient), blind studies (double blind experimenter and participant don’t know who is obtaining the active ingredient and who is obtaining the placebo)
• Treatment interventions use placebo effects (make sure participants are blind to the treatment they are exposed to)
External Validity (EV)
• How well findings relate to “real world”
• Enhance EV by ensuring that samples in our study relate closely to the sample we would like our findings to apply to
Research strategies: Duration
Cross-sectional
• study the relationships/effects at one point in time
• only examine a participant once
Longitudinal
Single-subject research
• Case Studies: detailed exploration of rare events (ex. P. Gage)
• Help generate causal hypotheses
• Allows test of causal hypotheses
• Difficult to generalize to others
Multiple Subject Observational Research
• Population Studies (e.g. epidemiological NCS-R)
• Note: Prevalence is always greater than incidence
• Multiple group studies: Correlation
• Correlational research style o defining characteristics of interest o Question is: is the correlation meaningful?
Negative correlation
Zero correlation