Imaging genomics and response to treatment with antipsychotics in schizophrenia

Recent important advancements in genomic research have opened the way to new strategies for public health management. One of these questions pertains to how individual genetic variation may be associated with individual variability in response to drug treatment. The field of pharmacogenetics may have a profound impact on treatment of complex psychiatric disorders like schizophrenia. However, pharmacogenetic studies in schizophrenia have produced conflicting results. The first studies examined potential associations between clinical response and drug receptor genes. Subsequent studies have tried to use more objective phenotypes still in association with drug receptor genes. More recently, other studies have sought the association between putative causative or modifier genes and intermediate phenotypes. Thus, conflicting results may be at least in part explained by variability and choice of the phenotype, by choice of candidate genes, or by the relatively little knowledge about the neurobiology of this disorder. We propose that choosing intermediate phenotypes that allow in vivo measurement of specific neuronal functions may be of great help in reducing several of the potential confounds intrinsic to clinical measurements. Functional neuroimaging is ideally suited to address several of these potential confounds, and it may represent a powerful strategy to investigate the relationship between behavior, brain function, genes, and individual variability in the response to treatment with antipsychotic drugs in schizophrenia. Preliminary evidence with potential susceptilibity genes such as COMT, DISC1, and GRM3 support these assumptions.