Is there a common basis between psychiatric and somatic diseases

There is increasing knowledge about considerable comorbidity between psychiatric and somatic diseases, questioning whether variations in genes could be predisposing factors for both conditions. With respect to the multiple interactions between brain and body, especially variants in several candidate genes for proteins were so far investigated, which mediate these crosstalks and have thus also implications in psychiatric disorders. The available data, although still preliminary and rare, implicate the importance of polymorphic variants in genes coding for the serotonin transporter (5-HTT), the 5-HT2A receptor, for proinflammatory cytokines as well as for the angiotenson-converting enzyme (ACE) in migraine, fibromyalgia, cardiovascular disorders and in psychiatric conditions. The role played by these various polymorphisms remains to be determined, as to whether they are indicative for common pathophysiological mechanisms, or identifying a subgroup of patients with somatic disorders, that are more closely related to psychiatric symptoms. Nevertheless, they do at least illustrate the potential influence of genetic differences on illness course and treatment outcome and might be a rationale approach to drug development and treatment paradigms.