Weissman et al.

What was the aim of Weissman et al. (2005)?

To study the potential genetic nature of Major Depressive Disorder (MDD).

What research design did Weissman et al. use?

A longitudinal family study.

How many participants were involved in the study?

A sample of 161 grandchildren, their parents, and grandparents.

How long did the Weissman et al. study last?

20 years.

What types of families were compared?

Families at high and low risk for depression.

How did researchers collect data?

From clinicians blind to past depression diagnoses and previous interview data.

What methodological control was used to strengthen reliability?

Researcher triangulation.

Who evaluated the children in the study?

Two experienced clinicians.

What did Weissman et al. find in grandchildren with two generations of major depression?

A high rate of psychiatric disorders.

By what age did many grandchildren show psychiatric symptoms?

By age 12, 59.2% showed signs of a psychiatric disorder.

What condition increased risk of disorders in children?

Having both a depressed parent and a depressed grandparent.

What was the effect if only the parent was depressed but grandparents were not?

No significant effect of parental depression on the grandchildren.

(+) What was a key strength of the Weilman et al. study?

High reliability due to longitudinal design and triangulation.

(-) What was a key limitation of the study?

Low internal validity due to possible confounding from time spent with healthy grandparents.

What potential confounding variable may have influenced results?

The amount of contact between children and healthy grandparents.