Association analysis of two dopamine D2 receptor gene polymorphisms and p300 event-related potential in depressive patients.

Previous Western studies have demonstrated an association between the dopamine D2 receptor (DRD2) TaqI A polymorphism and components of P300 event-related potential. This finding was not replicated in our previous study of a sample of normal young Chinese females, however. In the current study of 105 patients diagnosed with major depression, we have further explored the association between the P300 components, and, the DRD2 TaqI A polymorphism and another functional DRD2 -141Cins/Del polymorphism. The results demonstrate that neither polymorphism is associated with P300 amplitude or latency, even after gender analysis. We suggest that these two DRD2 polymorphisms have no major effects on P300 components for the Chinese population. The association between the DRD2 polymorphism and P300 components may depend on ethnicity, the psychiatric state of the subjects, or the investigative paradigms used.