To the Editor: My colleagues and I thank Drs. Sumiyoshi and Meltzer for commenting on our study, and we agree with them when they say that our results extend their previous observations with schizophrenic patients (Sumiyoshi et al., 2001). They comment that we failed to mention the discrepant results regarding the effect of the lower dose (30 mg/day) of tandospirone on memory performance, i.e., the facilitative influence in their studies versus the partially inhibitory effects in our study reported in the Journal. However, the patients in their study received tandospirone, 10 mg t.i.d., while the subjects in our study received the 30 mg of tandospirone at one time. Because of this difference, we cannot directly compare their results with ours. Previous studies have shown that the half-life of the plasma concentration of tandospirone was relatively short (1.2–1.4 hours), and the effect of the accumulation of this drug is reported to be negligible when the subjects received 10 mg t.i.d. of tandospirone for more than 3 months (1, 2). From this point of view, the plasma concentration of tandospirone in their studies might have been lower than that of ours.