Structural changes, regional cerebral blood flow disturbances, and metabolic disorders in the frontal and temporal lobes of the brain as well as in basal nuclei have been reported in schizophrenic patients. Smooth pursuit eye movement disorders suggest dysfunctions of subcortical structures. Moreover, an increased activation of the left cerebral hemisphere is found in schizophrenia, while an enhanced activation of the right cerebral hemisphere is reported in depression. The paper presents, firstly, results of neuropsychological tests assessing, among other things, the frontal lobe junctions, and secondly – neuropsychological examinations results allowing to evaluate activation level of the cerebral hemispheres. Two groups were compared in the study: schizophrenic patients (N=20) and those with endogenous depression (N=27). The examination was conducted in the state of symptoms exacerbation, prior to starting medication. The neuropsychological examination indicated a more pronounced frontal lobe dysfunctions in schizophrenic patients as compared to depressive subjects. Neuropsychological tests indicated an increased activation of the left cerebral hemisphere in schizophrenic patients, and of the right cerebral hemisphere in patients with depression.