Gene Environment Flashcards
Parental influence
Eley & Napolitano 2010
Childhood anxiety evoke maternal control
(Gene interaction correlation)
538 children age 8
Mothers observed participating in an etch-a-sketch task from which maternal control was rated. Children rated their anxiety using the screen for child Anxiety Related Emotional Disorders.
Results ~ children who experienced maternal behaviour rated as extreme control reported higher levels of anxiety.
The overlap between high child anxiety and maternal control was primarily due to shared genetic factors.
The results suggest that maternal control is likely to have been elicited by children with high levels of anxiety.
Gene environment correlation
Harden & Hill 2008
Gene environment correlation and interaction in peer effects on adolescence alcohol and tobacco use.
The interplay of genetic liability and peer influences on the development of adolescent alcohol and tobacco use was identified.
Examined using a nationally representative sample of adolescent sib,I got pairs and their best friends.
Results ~ genetic factors, adolescents own substance use and independent use were associated with increased exposure to best friends with heavy substance abuse (correlation).
Adolescents who were genetically liable to substance use were more vulnerable to the adverse influences of their best friends (interaction).
Gene environment interaction
Caspi 2005
Adolescence onset cannabis use on adult psychosis
Some people are genetically vulnerable to the deleterious effects of cannabis. Longitudinal design of a representative birth cohort why cannabis use is associated with the emergence of psychosis in a minority of users.
Results ~ findings provide evidence of a gene environment interaction and suggest there is a role of some susceptibility genes which influence vulnerable environmental pathogens.
The equal environments assumption
Hettema & Neale 1995
In twin studies of psychiatric disorders
Equal environments assumption was examined for the impact of psychical similarity on phenotypic remembrance in five common psychiatric disorders (major depression, generalised anxiety disorder, phobia, alcoholism and bulimia).
882 female pairs.
Results ~ structural equation modelling of the date using physical similarity as a form of specified common environment provided no evidence for a significant effect of psychical resemblance, thereby supporting the validity of the EEA in twin studies of these disorders.
Chorionicity
Dubé 2002
Monochirionicity increases the risk of adverse perinatal outcome, whereas the effects of zygosity are less clear
Genome Wide Association Study
Neuroticism
De Moor & Marleen 2015
To identify genetic variants associated with neuroticism by performing a meta analysis of genome wide association results based on 1000 genomes.
To evaluate whether common genetic variance as assessed by single nucleotide polymorphisms explain the variation in neurotics by estimating SNP based heredity that predict neuroticism and predict MDD.
30 cohorts with genome wide personality and MDD data from the genetics of personality consortium.
Results ~ common genetic variance explains 15% of the variance in neuroticism.
Identifies a novel locus for neuroticism - variant located in a known gene that has been associated with bipolar disorder and schizophrenia in previous studies.
Neuroticism is influenced by many variants of small effect. Genetic variants also influence MDD.
