Chapter 4: research methods in psychopathology

why is it difficult to make an objective study of psychological disorders? (2)

• complexity of human nature

• we cannot get inside someone’s mind (not directly at least)

define “hypothesis”

what you expect to find

define “research design”

how you want to the test your hypothesis

define “internal validity”

extent to which we are confident that the IV causes the DV to change

define “external validity”

how well the results describe things outside of the study/lab

what’s the difference between internal and external validity?

• internal: how sure are you that the IV causes the DV to change?

• external: how well your study describes things on the outside world?

true or false: hypotheses aren’t based on previous research

false: they are

define “testability”

ability to corroborate or reject the hypothesis

what’s the difference between a dependent variable, an independent variable and a confounding variable?

• DV: measured

• IV: manipulated

• confounding: changes the DV, but isn’t the IV (makes the results uninterpretable)

define “confounding variable”

a variable other than the IV also affects the DV, which makes the results uninterpretable

what are the strategies used by scientists to ensure internal validity? (3)

• control group: have a group that doesn’t go through the treatment

• randomization: randomly put everyone in different conditions

• analogue models: create conditions similar to what we want to study in the lab

define “control group”

people who are similar than those in the experimental group, but won’t be exposed to the independent variable like those in the experimental group

why do we have control groups?

because they want to compare people who receive the treatment with people who go through similar experiences except for the treatment

define “randomization”

process of assigning people to different condition so that everyone has an equal chance of being placed in any group

define “analogue models”

in the controlled conditions of the laboratory, create aspects that are comparable (analogous) to the phenomenon under study

define “generalizability”

extent to which results apply to everyone with a disorder

true or false: internal and external validity are correlated

false: they are inversely related

define “statistical significance”

mathematical calculation about the difference between groups

define “clinical significance”

whether or not the difference was meaningful for those affected

what’s the difference between statistical and clinical significance?

• statistical: calculation about the difference between groups

• clinical: whether the difference was meaningful

define “effect size”

how large is the difference between groups

define “social validity”

obtaining input from the person being treated and their significant others about the importance of changes that have occurred

define “patient uniformity myth”

tendency to see all patients as one homogenous group

what’s the problem of patient uniformity myth?

it leads researchers to make inaccurate generalizations about disorders in their treatments

define “case study method”

investigating intensively one or more individuals who display behavioural and physical patterns

true or false: the case study method uses scientific method

false: case study method relies on a clinician’s observations between

• someone with a disorder

• someone with another disorder

• someone with no psychological disorder

true or false: as psychological knowledge of disorders grows, we rely less on case study method

true

what are the limitations of case study?

• coincidences: case studies don’t control everything. sometimes, someone’s result is caused by a special combination of factors that isn’t obvious

• one study’s conclusion isn’t applicable for everyone

define “correlation”

statistical relationship between two variables

what does “correlation does not imply causation” mean?

two things occurring together doesn’t mean that one caused the other

what’s the difference between a positive correlation and a negative correlation?

• positive: higher score in one variable is associated with higher score in the other variable OR lower scores in one variable is associated with lower scores in the other variable

• negative: the relationship between the variables is reversed

the correlation coefficient can vary from […] to […]

-1.0 (negative correlation) to +1.0 (positive correlation)

define “epidemiology”

study of the incidence, distribution and consequences of a problem in a population (why does the disorder exist?)

define “incidence” of a disorder

estimated new cases during a period

define “prevalence” of a disorder

the number of people with a disorder at any time

what’s the difference between the incidence and the prevalence of a disorder?

• incidence: new cases during a specific period

• prevalence: how many people with a disorder at any time

true or false: epidemiologists also study the incidence and prevalence of disorders among different groups of people

how can you recognize a correlational study?

if we don’t manipulate the IV

define “experiment”

manipulation of an independent variable and observation of its effects

what’s the difference between an experimental design and a correlational design?

• experimental: change the IV and see how the behaviour of people is affected

• correlational: how different variables are associated

define “clinical trial”

experimental design used to determine the effectiveness and safety of a treatment

true or false: a clinical trial is a research design

false: it’s a method of evaluation that follows a number of rules (how to select participants, how to group them, how to analyze data…)

what’s the difference between “randomized clinical trials”, “controlled clinical trials” and “randomized controlled trial”

• randomized clinical trial: randomization of participants into each group

• controlled clinical trials: rely on control conditions for comparison

• randomized controlled trial: use both randomization and one or more control conditions.

why do we have control groups?

it allows the researcher to see if the treatment truly had an effect

true or false: control groups should be different from treatment groups

false: both should be similar

define “placebo effect”

when the behaviour changes because of the person’s expectation and not manipulation

when does resentful demoralization happens and what’s the problem with it?

• happens when people in the control group are disappointed that they aren’t receiving treatment

• can score worse on post-treatment measures

what are “placebo control groups” and why do we have that?

• a placebo will be given to the control group to make them believe that they are getting the treatment

• it’s to prevent the resentful demoralization

define “double-blind control”

when both the experimenter and the participant don’t know in which condition the participant is placed to avoid any bias from the experimenter

define “allegiance effect”

when the experimenter acts a certain way with the participant because they know in which group the participant is placed (can bias them positively or negatively)

define “comparative treatment research”

comparing groups/treatments instead of no-treatment and placebo control groups

what does process research focus on?

on the mechanisms responsible for behavioral changes

define “repeated measurements” and explain why they are important

• behaviour is measured several time instead of one

• it helps us know if the treatment is the reason for the change

explain the withdrawal design

• we want to see if the IV is responsible for the changes in behaviour

• we start at baseline, treatment and then return to baseline

• the withdrawal shows whether the treatment is effective

define “baseline”

condition before treatment

why are withdrawal designs not always ideal? (2)

• you might to remove an effective treatment (not ethical)

• it doesn’t work of the treatment cannot be removed (ex: to control anxiety, we say that the treatment is to imagine yourself on the beach. how do you remove that?)

define “multiple baseline”

starting the treatment at different times across settings, behaviours or people”

true or false: internal validity doesn’t change with multiple baseline

false: it improves

interaction between our […] and our […] determine how we will develop

interaction between our genetic makeup and our experiences determine how we will develop

what’s the difference between phenotype and genotype?

• phenotype: gene that makes up a characteristic or behaviour

  • ex: gene for eye colour

• genotype: the genetic makeup, the result of the phenotype

  • ex: the colour of our eyes

the gene that makes up our height is the [genotype/phenotype] while our height is the [genotype/phenotype]

• gene = phenotype

• height = genotype

define “genome”

all the genes of an organism

explain the human genome project

work that identified hundred of genes that contribute to inherited diseases

define “endophenotypes”

genetic mechanisms that contribute to the underlying problem causing the symptoms and difficulties experienced by people with psychological disorders

true or false: when looking at a schizophrenic person, we try to look for their “schizophrenia gene”

false: we try to look for the endophenotypes (genes that cause working memory problems or other problems)

define “family studies”

examining a behavioural pattern or emotional trait in the context of the family

define “proband”

family member with the trait used in family studies

true or false: if genetics influence mental disorders, the trait should occur on all family members equally

false: trait should occur more often in first-degree relatives (parents, siblings, kids) than in second-degree and more distant relatives

what’s the problem with family studies?

family members live together, so there might be something shared in the environment that “causes” the disorder

• ex: you fear spiders because your mom always screamed to death when she saw one, which you will now transmit to your kid

define “adoption studies”

• technique to separate environmental for genetics

• scientists identify adoptees with behavioural pattern or psychological disorder and try to find first-degree relatives who was raised in different settings

define “epigenetics markers”

change in chemical markers in the womb which causes subtle differences (even for monozygotic/identical twins)

define “twin studies”

trying to understand whether identical twins share the same traits more often than fraternal twins

twin studies aren’t perfect as twins often grow in the same environment, and we know how important the environment is to the development. how could we solve this problem?

by doing a mix of adoptions study and twin study

what are the ways to locate a gene that could possible cause a mental disorder? (2)

• genetic linkage analysis: observe family disorder and genetic markers

• association studies: compare the genetic makers of people with a disorder and people without that disorder

true or false: both strategies used to locate a gene for a mental disorder have made science progress

false: we often weren’t able to reproduce the results

explain “genetic linkage analysis”

• we study a family disorder and genetic markers

• if there is a link between the inheritance of a disorder and the inheritance of a genetic makers, both the gene of the disorder and the marker are probably on the same chromosome

explain “association studies”

• we compare the genetic markers of people with a disorder and people without that disorder

• if there are certain markers more present in people with disorder, we assume that the markers are close to the genes involved with the disorder

define “polygenic scores”

there are multiple genes involved in a psychological disorder, but they individually only have a small effect

define “genetic markers”

inherited characteristics (that aren’t necessarily disorders)

why is it beneficial to understand how a disorder changes or remain the same over time? (3)

• decide if we treat the person

• if we understand the changes, we can understand how problem were created

• design interventions to prevent the problem

what’s the difference between prospective and retrospective studies?

• prospective: record changes as it occurs

• retrospective: ask people what happened in the past

[prospective/retrospective] study is better than [prospective/retrospective]

prospective is better than retrospective

what are the possible prevention research? (4)

• positive development strategies/health promotion: for the entire population, even those not at risk

• universal prevention strategies: for the entire population, but we target certain risk factors

• selective prevention strategies: for certain groups at risk

• indicated prevention strategies: for those who begin to show symptoms, but not yet the psychological disorder

define “health promotion” or “positive development strategies”

• prevention for the whole population, even those not at risk

• we prevent later problems and promote protective behaviour

define “universal prevention strategies”

• prevention for the entire population

• we target certain factors, but not people

define “selective prevention”

• prevention for people at risk

• specific intervention to avoid future problem

define “indicated prevention”

prevention for people who already have the symptoms, but not the psychological disorder yet

define “cross-sectional design”

take sections of a population across different ages and compare them on some characteristics

define “cohorts”

participants in each age group of a cross-sectional design

define the “cohort effect”

limitation of the cross-sectional design, difference amongst cohorts because of their cognitive and emotional development (each cohort lived through things differently)

what’s a pro of cross-sectional designs and a pro of longitudinal designs?

• cross-sectional: easier to use

• longitudinal: no cohort effect + asses individual changes

define “longitudinal designs”

researchers follow one group over time and asses changes to each member

what’s the difference between cross-sectional and longitudinal designs?

• cross-sectional: different ages at the same time

• longitudinal: same people across time

what are the cons of longitudinal studies? (2)

• costly and time consuming

• cross-generational effect: trying to generalize findings to people with different experiences

define “cross-generational effect”

generalizing findings to groups who had different experiences than participants

define “sequential design”

repeated study of different cohorts over time (mix of cross-sectional and longitudinal)

why is it important to consider/understand different cultures? (3)

• the definitions of a mental disorder changes

• behaviours are expressed differently

• we have different treatment models

true or false: some research approaches are better than others

false

true or false: we resolve significant issues with one large perfectly designed study

false: we solve it with a program research

define “program research”

series of studies that that examine different aspects of a problem