Association analysis between the C-1291G polymorphism in the promoter region of the adrenergic alpha2A receptor gene and polydipsia in schizophrenia.

Several lines of studies have shown the existence of an important inhibitory mechanism for the control of water intake involving adrenergic alpha2A receptors (ADRA2A). A human study using patients with schizophrenia demonstrated an exacerbation of polydipsia by the administration of clonidine, an ADRA2A-agonist, and a relief of polydipsia by mianserin, an ADRA2A-antagonist, suggesting the involvement of the central adrenergic system in the drinking behavior of patients with schizophrenia. Based on these findings we examined a possible association between the C-1291G polymorphism in the promoter region of the ADRA2A gene and polydipsia in schizophrenia using a Japanese case-control sample. Our sample includes 348 patients with schizophrenia (DSM-IV) (84 with polydipsia and 264 without polydipsia). No significant association between the ADRA2A C-1291G polymorphism and polydipsia was found. Our result suggests that the ADRA2A C-1291G polymorphism may not confer susceptibility to polydipsia in schizophrenia in our sample. Further studies with larger samples are warranted.