We have further studied a previously investigated sample of 187 major depressive disorder (MDD) patients, 171 bipolar disorder (BD) patients, and 288 controls, and tried to analyze the interaction between a set of variations of independent genes: the trace amine receptor 6 (rs4305745, rs8192625, rs7452939, rs6903874, and rs6937506) and the heat shock protein 70 (rs562047, rs1061581, rs2227956).