We performed a retrospective study in a group of 296 teenage patients treated for schizophrenic psychoses in our department between 1997 and 2007.22 The time to first improvement could be estimated in 258 patients; of these, 195 (76%) had been treated with AAPs and 63 (24%) with typical antipsychotics. The mean time to first improvement was 6.9 days in the AAP group and 5.8 days in the typical antipsychotic drug group; the difference was significant at the trend level (P=0.063). With respect to individual drugs, the mean time to first improvement was 7.1 days for risperidone, 6.7 days for olanzapine, 6.5 days for ziprasidone, 6.1 days for quetiapine, 7.4 days for clozapine, 5.2 days for haloperidol, 5.9 days for perphenazine, and 6.0 days for sulpiride. Differences between the drugs were not significant.