Understanding the roles of genome and envirome: methods in genetic epidemiology

Background In order to understand studies of psychiatric epidemiology focus ing on the 'genome' and 'envirome', basic knowledge of the logic and method s 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 interactio n are also discussed. Results Quantitative genetic studies indicate that genetic influences are i mportant for both psychiatric disorders and behavioural traits. Specific ge ne loci can be tested for associations with both psychiatric risk and behav ioural traits by means of molecular genetic techniques. There has been litt le examination of genotype-environment correlation and interaction, althoug h the few reports that have appeared suggest that these complex relationshi ps are important. Conclusions Advances in quantitative and molecular genetics now permit more careful examination of genotype environment interaction and correlation. S tudies combining molecular genetic strategies with measurement of the envir onment are still at an early stage, however, and their results must be awai ted. Declaration of interest None.