Influence of methodology of studies on assessment of psychopharmacological effects on cognitive functioning in patients with schizophrenia

Novel antipsychotic medications have been reported to have beneficial effects on cognitive functioning in patients with schizophrenia. However, these effects have been assessed in studies with considerable variation in methodology. Methodologies for assessing cognitive change in patients with schizophrenia in different foreign studies were analyzed. Methodological weaknesses that limit the interpretability of the influence of antipsychotic drug on cognition are discussed. Methodological recommendations from different foreign publications used in independent pharmacological clinical trials are reported. Also the results of these pharmacological studies performed in Europe and USA are discussed. In these pharmacological studies the methodological recommendations were taken into consideration.