JPBS

Incorporating a genetic component can be appealing to an investigator designing a new study of a neuropsychiatric disorder. After all, it is well known that most neuropsychiatric disorders are heritable to one degree or another. One may consider genetic study a simple process: draw blood from subjects, submit it to a service lab, get the genotypes back, and test them for an association with the phenotype(s) being studied. In reality, it is considerably more complicated than that. Putting aside the complexity of choosing the proper platforms for genotyping and phenotyping, there are a number of issues that must be addressed in the initial study design if the results are to be replicable and relevant to the current state of knowledge of the disorder in question. The three major issues are effect sizes, Type I error rates, and genetic and phenotypic heterogeneity.