The influence of media violence on youth

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83429/1/2003.Anderson_etal.InfluenceofMediaViolenceonYouth.PsychologicalScienceinthePublicInterest.pd

Stroke and apolipoprotein E (4 are independent risk factors for cognitive decline: a population-based study.

Background and Purpose —Stroke and apolipoprotein E ε4 (ApoE ε4) are individually important risk factors for cognitive decline, including Alzheimer disease. It has been suggested that ApoE ε4 multiplies the risk for cognitive decline following stroke. In a population-based sample, using well-defined sensitive cognitive measures, this study investigates whether cognitive decline following stroke is worse for patients who carry the ApoE ε4 allele. Methods —Subjects were participants in the Longitudinal Aging Study Amsterdam (LASA). The sample consisted of 1224 subjects, aged 62 to 85 years, who participated in the 3-year follow-up examination and for whom ApoE and stroke data were complete. We assessed cognitive decline using the Mini-Mental State Examination, the Auditory Verbal Learning Test (memory: immediate and delayed recall), and the Coding Task (information processing speed). The effects of stroke and ApoE ε4 on cognitive decline were evaluated with ANOVA and multiple logistic regression analysis, adjusted for age, sex, education, and baseline cognition. Results —A synergistic effect modification for stroke and ApoE ε4 on cognitive decline was not observed. Unexpectedly, instead, stroke patients carrying the ε4 allele demonstrated a nonsignificantly lowered risk for Mini-Mental State Examination decline (OR=0.3; 95% CI 0.1 to 1.1). ApoE ε4 was associated with declines in information processing speed (OR=1.5; 95% CI 1.1 to 2.1) and small declines for immediate and delayed recall. Conclusions —Stroke and ApoE ε4 may impair cognition through distinct nonsynergistic mechanisms. The slowing of information processing speed for ApoE ε4 carriers was more evident than impairment in memory. </jats:p

A behavioural genomic analysis of DNA markers associated with general cognitive ability in 7-year-olds

Background:  Five DNA markers (single-nucleotide polymorphisms, SNPs) have recently been found to be associated with general cognitive ability (‘g’) in a sample of 7414 7-year-old twins. These children have also been studied at 2, 3, 4, and 7 years of age on measures of cognitive and language development and behaviour problems; family environment was also assessed. Methods:  We used these data to conduct a behavioural genomic analysis of the five SNPs and a composite of them (‘SNP set’) that explored developmental, multivariate, and genotype–environment (GE) issues. Results:  The ‘g’ SNP set identified at 7 years yielded significant associations with ‘g’ as early as 2 years. In multivariate analyses at 7 years, the ‘g’ SNP set was more strongly associated with verbal than nonverbal ability and with reading more than mathematics performance. GE correlations were found between the SNP set for ‘g’ at 7 years and preschool proximal measures of the family environment (chaos and discipline) rather than distal measures (maternal education and father's occupational class), suggesting evocative rather than passive GE correlation. Significant GE interactions were found for discipline, education and occupation in which the association between the SNP set and ‘g’ at 7 years is stronger in low-risk environments. Conclusions:  Although the effect sizes of the five SNP associations are very small, behavioural genomic analyses using a ‘g’ SNP set illustrate how developmental, multivariate and GE questions can be addressed as more DNA associations are identified for complex traits such as ‘g’