Contemporary researches of the cognitive impairment in schizophrenic patients were conducted in three directions: Cognitive declining as a developmental precursor of schizophrenia, evolution of the cognitive deficit during the illness, and at last, impact of pharmacological treatment on cognitive functioning. The main aim of our study is to evaluate differences between first and second-generation antipsychotics in manifestations and course of the cognitive declining, in patients with first episode of paranoid schizophrenia.

We conducted open label, prospective trial, at the sample of 12 patients during first episode of paranoid schizophrenia. Diagnosis was made according to the criteria of the International classification of diseases 10th revision. The sample was divided in two clusters with 6 patients in each one. In the first cluster, patients received first-generation antipsychotics, and in the second one was administered second-generation antipsychotic - risperidone. Cognitive functions was evaluated by Mini Mental State Examination Test which is modified with adding two simple neuropsychological tests: Clock Drawing Test and Test of Verbal Fluency.

We found more prominent cognitive declining in first cluster patients - particularly mnestic deficit.

First-generation antipsychotics posses more prominent negative impact on cognitive functioning in comparison to second generation antipsychotic - risperidone.