The completion of the Human Genome Project (International Human Genome Sequencing Consortium 2004) provided 3 billion bases of reference nucleotides for comparative genetic studies that will fundamentally alter how diseases are defined, prevented, and treated (Guttmacher and Collins 2002). In addition to Homo sapiens, hundreds of other species have now had their genomes sequenced, with many more in progress (see National Center for Biotechnology Information 2008). In 2007, the first genetic sequences of living individuals were reported; personalized genomics is upon us (Levy et al. 2007). There is every reason to believe that this revolution will impact geriatric psychiatry. Family, twin, and adoption studies have demonstrated robust genetic influences in geriatric psychiatric disorders including schizophrenia, bipolar disorder, and Alzheimer's disease (AD). Conventional genetic approaches have advanced our understanding of the nature of the genetic contributions to these disorders. These gains have been hard won, and limited so far. However, the pace of discovery is notably quickening in this new postgenomics era. To prepare the reader for what lies ahead, we have therefore undertaken the task of summarizing key advances in genomic science and the current state of understanding of the genetics of mental disorders of aging.