DRD3 and psychotic disorder: Here, we measured the mRNA expression status of dopamine receptor D2 (DRD2), DRD3, and dopamine and cyclic adenosine 3′,5′-monophosphate regulated phosphoprotein-32 (DARPP-32) in T lymphocytes of patients with early psychosis by quantitative real-time polymerase chain reaction (q-PCR) and explored the relationships between their mRNA levels and the psychopathological status of patients.