4.4 SUMMING UP

Using the Scientific Method to Understand Abnormality

• Researchers use the scientific method to understand and study psychopathology. In doing so, they observe relevant phenomena, identify a question to be answered, develop and test hypotheses that might answer the question, draw on the evidence to formulate a reasonable theory, and test the theory.
• Researchers systematically manipulate one or more independent variables (changing one at a time) and observe possible changes in the dependent variable(s). Researchers note how changes in the independent variable(s) are accompanied by changes in the dependent variable(s). In addition, researchers examine the possible contribution of confounds by using control groups or control conditions. To minimize unintentional bias, they randomly assign participants to groups and choose stimulus items to minimize confoundings. Experiments should have both internal and external validity.
• When random assignment is not ethical, desirable, or possible, the researchers may use a quasi-experimental design.
• Correlational research is used when independent variables cannot or should not be manipulated. Such studies allow researchers to investigate the relationship between two variables and note whether a change in one variable is associated with a change in the other. However, a correlation does not imply causation; it only indicates that the two variables are related.
• Case studies allow clinicians and researchers to examine one individual in detail. However, information from a particular case may not generalize to others.
• Meta-analysis allows researchers to aggregate the results of a number of related studies in order to determine the relations among certain variables.
• Psychologists have developed an ethical code of conduct that lays out guidelines for research, including that the research must be approved by an IRB, informed consent must be obtained from participants, and participants must be debriefed after a study is over.

Research Challenges in Understanding Abnormality

• Many studies that focus on neurological factors are correlational and so do not reveal how neurological factors may cause psychological disorders.
• Researchers must take care in phrasing questions in order to minimize various types of biases.
• Challenges in studying social factors can create challenges in studying other types of factors. Such challenges include experimenter-influenced biases, such as experimenter expectancy effects and reactivity.

Researching Treatment

• When studying medication, a placebo effect—rather than a true drug effect—may influence the results. Attrition rates can also distort the apparent effects of a treatment.
• A treatment may be effective because of common factors, as well as because of specific factors unique to that treatment. Control groups can allow researchers to examine specific factors and to rule out possible effects of some confounding variables. In general, therapy is more helpful than no treatment, but some specific therapies are better than others for some particular disorders.
• Some studies use a randomized clinical trial (RCT) design, which allows researchers to investigate the efficacy of specific factors or treatments; a RCT typically involves manual-based treatment. The results of such research generally suggest a dose–response relationship.
• Research on treatments that target social factors reveals that matching patients and therapists by ethnicity, gender, or age does not systematically alter the effectiveness of therapy. For patients with a strong preference, however, matching may lead to a better outcome.