Assigned articles Flashcards
Kendler
Question: To what degree do stressful life events cause major depression?
Data: They bring data from over 15 classes of stressful life events and the onset of major depression over a 1-year period in female twins. The sample consists of 24,648 person-months and 316 onsets of major depression. The stressful events were rated on threat and dependence (the degree to which the stressful life event could have resulted from the respondent’s behavior)
the analytical approach used: co-twin control analysis
take home findings: Stressful life events have a substantial causal relationship with the onset of episodes of major depression.
Saunders
Question: what are the longitudinal effects and environmental moderation of ALDH2 and ADH1B gene variants on substance use?
Data: They bring in 412 genotyped adopted individuals of East Asian ancestry between the ages of 14 and 40.
Analytical approach: an adoption study with a longitudinal design
Take home findings: found strong associations between alcohol frequency, quantity, and maximum drinks and ALDH2, but not ADH1B. They also found that the magnitude of the ALDH2 protective effect increased with age, especially for maximum drinks. Finally, there was no strong evidence of associations between ALDH2 status and tobacco, marijuana, or illegal drug use. This is contrary to expectations if alcohol serves as a gateway to the use of other drugs.
Colodro-conde
question: Are adults with higher genetic risk for schizophrenia more likely to live in urbanized and populated areas than those with lower risk?
Data: They brought in four large samples of genotyped individuals of European ancestry older than 18 years with known addresses in Australia, the United Kingdom, and the Netherlands. They also brought in 5894 twins and 15544 participants from the QIMR sample.
Analytical approach: a cross-sectional study, twin models, polygenic scores, and mendelian randomization
Take home findings: participants living in more densely populated areas had a higher genetic loading for schizophrenia. individuals with increased genetic risk tend to live in urban/dense areas and suggest the need to refine the social stress model for schizophrenia by including genetics as well as possible gene-environment interactions.
