The practice of psychiatry has long suffered from the limited information available on the biological basis of mental disorders. This limitation is now coming to an end. Advances in DNA analysis technologies and in our understanding of the human genome, together with our new knowledge of the properties of the genome and significant efforts toward generating large patient and control sample collections, have paved the way for successful genome-wide association studies. As a result, reports now appear in the literature every week identifying new genes for complex disorders. Next-generation sequencing methods, combined with the results of association and perhaps linkage studies, will help us uncover missing heritability factors, achieve a better understanding of the genetic aspects of psychiatric disease, and devise the best strategies for incorporating genetics in the service of patients.