To study changes in attention and executive functions during psychopharmacotherapy in patients with paranoid schizophrenia, we have examined 120 patients with a first episode of paranoid schizophrenia treated with typical and atypical neuroleptics. Clinical and statistical analyses have revealed the heterogeneity within treatment groups that allowed to define two subgroups. These subgroups were characterized by a differed disease course (favorable or poor type). Before remission was achieved, the effect of atypical neuroleptics on cognitive performance was higher compared to typical neuroleptics. After remission, when doses of neuroleptics were decreased, a type of disease course played a main role. At 6 months after remission, attention and executive functions have improved in subgroups with favorable course of disease regardless of treatment.