At the same time, the data supporting the notion of cognitive blunting by antipsychotic medicines is largely negative (although limited in amount) and frequently badly out of date (see Ernst, Malone, Rowan, George, Gonzales, & Silva, 1998; Aman, 1984; Aman, Marks, Turbott, Wilsher, & Merry, 1991). There are good theoretical reasons to believe that novel antipsychotics may have no effects on cognition or may actually enhance cognitive functioning, at least in some disorders (Borison, 1996; Meltzer, 1995; Stip, 1996). At least one study thus far has shown significantly improved cognitive performance in schizophrenic patients taking risperidone as compared with such patients taking high-potency classical antipsychotics or no treatment (Gallhofer, Bauer, Lis, Krieger, & Gruppe, 1996).