Research methods in Psychopathology

Question 1

Cross-sectional designs

Answer 1

Collect data from many different individuals at a single point in time. Check correlations. Observe variables without influencing them. Can make NO causal claims.

Question 2

Longitudinal designs overcome is better than cross-sectional designs in which aspect?

Answer 2

Can try to establish temporal precedents. What comes first?

Question 3

Types of Longitudinal Designs (3)

Answer 3

(1) Retrospective
(2) Follow-Up Studies
(3) High Risk Studies

Question 4

Retrospective design

Answer 4

Type of Longitudinal Design. Collect a sample of people with a disorder. Try to determine what preceded it.
=> Self report + Existing data (school records, biological…)

Question 5

Cons of retrospective design (2)

Answer 5

(1) Problem of recall
(2) Lack of control over the data that you get. Not everyone has these records.

Question 6

Follow-Up Studies def

Answer 6

Type of Longitudinal Design. Follow people with the disorder over time. See what happens to them. Already-ill sample. Understand the natural course of the disorder.
=> Can’t derive etiological explanations but helpful for understanding whether the “ill” correlations persists outside the illness state.

Question 7

High Risk Studies

Answer 7

Type of Longitudinal Design. Variant of follow-up. Identify people who arelikelyto develop a disorder.
Rly hard to do. Offspring of people with a disorder (genetic) - Follow them over time.

Question 8

Cons of High-risk studies (3)

Answer 8

(1) Genetic: Need to find people who have the disorder + have children. Hard.
(2) Biological: Associations not well-proven. We don’t have a lot of biological abnormalities that we know are associated strongly w the dev of psychopathology.
(3) Behaviors: May be a risk factor OR early manifestation of the disease

Question 9

What are the characteristics of a Vulnerability Marker? (3)

Answer 9

(1) Should be trait-like, not state-related. If something ONLY appears when pple are ill, it’s a (passive) correlate/ symptom of the illness.
(2) Ideally, marker should PRECEDE illness, be there DURING illness and be there AFTER illness. => Has to be correlated with the disorder, but has to persist beyond the end of the episode. Could be a scar.
(3) Has to be present in a high-risk population.

Question 10

Episode markers

Answer 10

Are ONLY present in episode.

Question 11

Case Control design

Answer 11

Compare one group WITH thedisorder to a second groupWITHOUTthe disorder.
=> Tends to be most useful if the disorder is RARE. e.g. schizophrenia.

Question 12

Cohort design

Answer 12

A single large sample of people, some of whom have the disorder. You’re not trying to get as many pple as possible.
=> Preferable is disorder is not that rare. E.g. MDD
=> Allows you to compare it to pple with anxiety, cocaine use disorder or pple who don’t have any disorder at all.

Question 13

Patient populations are ___ representative of people with the disorder in the community. Why? (4)

Answer 13

NOT.
(1) Typically more severe bc treatment-seeking populations.
(2) Higher SES
(3) More likely to be girls
(4) Missing huge portion of pple who have the disorder
(5) Tend to have more comorbidities + chronic.

Question 14

Proband

Answer 14

Someone who HAS the disorder.

Question 15

In what ways (other than directly having the disease) we can see that a disorder runs in a family?

Answer 15

(1) Subthreshold/ symptoms: Even if i’m not depressive I may be MORE PRONE to depressive symptoms than the general population.
(2) Coaggregation: Disorders don’t run in families in a very specific ways. E.g. if you’re the proband with depression, depression run in family BUT ALSO higher rates of anxiety disorders than the general population.

Question 16

What are the 3 types of Adoption Studies?

Answer 16

(1) Parent as proband
(2) Adoptee as a proband
(3) Cross fostering design

Question 17

Adoption Studies: Parent as a proband

Answer 17

Group of parents: some of whom have the disorder of interest, some of whom do not, all of whom have given up children for adoption.
=> Then you go and look at their children and see: do those children have higher rates of the disorder than the general population? Do the parents of the pro bands with the disorder have higher rates of depression than the general population.

Question 18

Adoption Studies: Adoptee as a proband

Answer 18

Person adopted assessed for the disorder of interest. Then track down & assess both their adoptive and their biological parents.

Question 19

How is “Adoptee as a proband” particularly useful?

Answer 19

Helps disentangle environment from genetic risk.
=> If I have depression and I was adopted, do my adoptive parents more likely to have depression or my biological parents?

Question 20

Adoption Studies: Cross-fostering design

Answer 20

Swap:
Schizo parent + Adopted healthy
No schizo parent + Adopted schizo.
Most challenging of all.
=> Natural experiment!

Question 21

Additive Genetic Component (A)

Answer 21

Additive effect of many different genes that make up our psychological phenotype.
=> Heritability estimates can vary from 0 (no heritability) to 1 (absolutely heritable).

Question 22

Twin Studies are estimating 3 things, what are they?

Answer 22

A: Additive Genetic Component
C: Common Environment Component
E: Unique Environment

Question 23

Common Environment Component (C)

Answer 23

Any ENVIRONMENTAL factors that make twins SIMILAR to one another (regardless of zygosity). How much are they alike across both types of twins.

Question 24

Unique Environment (E)

Answer 24

How much do each member of the twin pair differ from one another due to unique environment factors.
E.g. experience one did have that the other didn’t

Question 25

How is A (Additive Genetic Component) calculated?

Answer 25

(Correlation in symptoms between MONOzygotic twins) - (Correlation in symptoms between DIZYgotic twins)
=> To what extent are monozygotic twins more similar to one another than dizygotic twins?

Question 26

Problems with Twin studies (5)

Answer 26

(1) MZ twins often share placenta: Implications for gene expression over the lifetime. Even at conception, environment of NZ twins is more similar than environment of DZ twins.
(2) MZ twins treated more similarly to one another
(3) Heritability doesn’t tell us what CAUSES the trait.
(4) Not deterministic: probabilistic
(5) Twin studies rarely ever model gene-environment interactions.

Question 27

What are the 3 types of Gene-Environment correlations (rGE)?

Answer 27

(1) Passive Gene-Environment correlations
(2) Active Gene-Environment correlations (aka niche-picking)
(3) Evocative Gene-Environment correlations (reactive)

Question 28

Passive Gene-Environment correlations

Answer 28

Association between the GENOTYPE a child inherits from his or her parents and the ENVIRONMENT in which the child is raised.
Passive bc it doesn’t depend on what the child does.
=> Can be addressed in adoption studies.

Question 29

Active Gene-Environment correlations (aka niche-picking)

Answer 29

People are not just passive receptacles of their environments.
They also contribute to their environment.
=> Selecting themselves into environment based on genetic risks.

Question 30

Evocative Gene-Environment correlations (reactive)

Answer 30

We’re treated differently based on our genetic makeup (e.g. ugly vs attractive, short vs tall).

Question 31

____ and _______ gene-environment correlations are hard to measure. Need better understanding of how environment shapes traits.

Answer 31

Active; evocative

Question 32

Currently, allrGE (Gene-Environment correlations) attributed to _____.

Answer 32

G = genes

Question 33

Paradox of Intelligence

Answer 33

IQ highly heritable: 80% (approx.). However, also malleable.
Flynn effect: intelligence increased across the 20th century. Developing countries

Question 34

How do we explain the Flynn effect?

Answer 34

Higher IQ = seek out“more stimulating”env.
=> As countries increase in development, these more stimulating things become more available.

Question 35

Heritability varies as a function of ______

Answer 35

environment.
E.g. Heritability of alcohol use for those residing in a neighborhood with ten or more alcohol outlets was 74%, compared with 16% for those in a neighborhood with zero outlets.

Question 36

Genotype → Phenotype gap

Answer 36

We don’t know how the additive genetic component contributes to the observed phenotype.

Question 37

Endophenotype

Answer 37

Something that lies along the pathway between genotype & phenotype.
Hidden trait that is NOT directly observable but contributes to the development of a VISIBLE or observable characteristic or condition.
=> E.g. In the case of schizophrenia, the overt symptom could be a psychosis, but the underlying phenotypes are, for example, a lack of sensory gating and a decline in working memory. Both of these traits have a clear genetic component and can thus be called endophenotypes.

Question 38

To be a endophenotype, it must: (6)

Answer 38

(1) Correlate with illness in the population.
(2) Be heritable (more in mono twins)
(3) Not be state-dependent (manifests whether illness is active or in remission)
(4) Co-segregate with illness within families
(5) Present at a higher rate within affected families
(6) Amenable to reliable measurement, and be specific to the illness of interest