It may be more straightforward to identify a new target via rare mutations, but it is often not clear whether manipulating these targets will be effective in the wider disease population. The common disease-associated polymorphisms identified by GWAS in psychiatry and other complex disorders also have the potential to identify novel drug targets as well as new aetiologies that can kindle the generation of new model systems for therapeutic development in the wider population.13 Several examples indicate that although GWAS loci have small effect sizes, they nonetheless may help identify targets for novel therapeutics, as shown in GWAS meta-analyses of lipid levels,14 or existing drugs that can be repurposed for the treatment of diseases that they were not initially developed to treat, an approach known as drug repositioning15,16. Integration of genetic data can be used for target selection, matching targets to indications while allowing a reduction in clinical trial costs such as by allowing more accurate identification of high risk individuals. Targets with genetic support have been shown to have a higher chance of success17.
