Understanding the roles of genome and envirome: Methods in gentic epidemiology

Background: In order to understand studies of psychiatric epidemiology focusing on the 'genome' and 'envirome', basic knowledge of the logic and methods is necessary. Aims: To provide a review of typical methods used in genetic epidemiology. Method Reviews of the research designs usually employed in quantitative and molecular genetic studies. Genotype-environment correlation and interaction are also discussed. Results: Quantitative genetic studies indicate that genetic influences are important for both psychiatric disorders and behavioural traits. Specific gene loci can be tested for associations with both psychiatric risk and behavioural traits by means of molecular genetic techniques. There has been little examination of genotype-environment correlation and interaction, although the few reports that have appeared suggest that these complex relationships are important. Conclusions: Advances in quantitative and molecular genetics now permit more careful examination of genotype-environment interaction and correlation. Studies combining molecular genetic strategies with measurement of the environment are stiff at an early stage, however, and their results must be awaited. Declaration of interest: None.