Twin Designs and Causal Inference in Genes and Behavior

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What is the purpose of matching in research studies?

To match treated individuals with controls to eliminate confounding variables.

What is genetic confounding?

When the exposure and outcome are both associated with a common genetic factor.

Why is causal inference important in psychopathology?

To identify causes of diseases as targets for interventions.

What is the difference between correlation and cause?

Correlation indicates a relationship between variables, while cause implies a direct influence of one variable on another. Signup and view all the answers

Give an example of misidentification in research studies.

Using self-reported smoking as a measure of exposure when some people misreport their smoking status. Signup and view all the answers

Why is no single research design sufficient for drawing conclusions?

Because different designs have different strengths and weaknesses. Signup and view all the answers

What is active gene-environment correlation?

When the exposure is influenced by the genotype. Signup and view all the answers

Give an example of passive gene-environment correlation.

A child raised by a smoking parent being exposed to second-hand smoke. Signup and view all the answers

What is reverse causation?

When the outcome causes the exposure, rather than the other way around. Signup and view all the answers

Explain the concept of counterfactual approach to theorize causal inference.

It involves considering what would have happened if a different treatment had been administered. Signup and view all the answers

How can active gene-environment correlation confound the relationship between exposure and outcome?

By making the genotype a cause of both the exposure and the outcome. Signup and view all the answers

In passive gene-environment correlation, how does the genotype of another person affect exposure?

The genotype of another person (e.g., parent) influences the exposure of the individual. Signup and view all the answers

What is the purpose of using a 'counterfactual' in research studies?

To compare the outcomes of a treatment group with those of a group that did not receive the treatment. Signup and view all the answers

How are twins often used as a proxy for a 'clone' in research studies?

Twins, especially monozygotic (identical) twins, share 100% of their genetic material and common environmental influences, making them ideal for comparing effects of exposures. Signup and view all the answers

What does it mean when twins are 'discordant' for a risk factor?

When one twin is exposed to a risk factor while the other is not, they are considered discordant. Signup and view all the answers

How can the effect of a treatment be estimated using the 'discordant MZ design'?

By comparing the outcomes of monozygotic (identical) twins who are discordant for an exposure or treatment. Signup and view all the answers

In what situations can the causal effect of an exposure be estimated using propensity score matching?

Propensity score matching can be used to estimate causal effects when there is a risk of confounding due to non-random assignment of exposures. Signup and view all the answers

Why is it important to consider genetic and environmental confounding when studying the relationship between stressful life-events and Major Depression?

Genetic and environmental confounding can distort the observed relationship between stressful life-events and Major Depression, making it crucial to account for these factors in the analysis. Signup and view all the answers