Comparison of Sustained Attention in Patients with Schizophrenia and Non-psychotic Major Depression with Healthy Individuals

Background & Objectives: Sustained attention deficit is one of the major cognitive complications caused by schizophrenia. Psychosis could influence the severity of sustained attention deficit in these patients. This study aimed to compare the level of sustained attention in patients with schizophrenia and non-psychotic major depression with healthy individuals. Materials and Methods: In this study, ۳۰ schizophrenic and ۳۰ nonpsychotic major depression patients were selected via available sampling from the referrals of Hafez and Ibn Sina hospitals in Shiraz, Iran. After patient matching, the normal group, consisting of ۳۰ healthy individuals, was selected via random sampling from the employees of the aforementioned hospitals. After diagnosis by a psychiatrist and structured clinical interviews based on DSM-IV (SCID-I) by a clinical psychologist, the subjects were divided into three groups. Sustained attention of the subjects was measured using continuous performance test (CPT). Results: Schizophrenic patients had a weaker performance on all the variables of CPT compared to non-psychotic major +depression patients and the normal group (P<۰.۰۰۱). In addition, there was a significant difference between the two patient groups in all three variables of the test (P<۰.۰۰۱), and sustained attention deficits were observed to be more severe among schizophrenic subjects. Conclusion: According to the results of this study, deficits observed in schizophrenic patients on CPT could be significantly associated with the presence of psychosis, which is considered as the specific profile of schizophrenia. Furthermore, given the level of sustained attention deficit in each group, early positive or negative prognosis could be obtained during the initial stages of these mental disorders.

Keywords:

Continuous performance test (CPT) , Non-psychotic major depression , Schizophrenia , Sustained attention , نگهداری توجه , اسکیزوفرنیا , افسردگی اساسی بدون روان پریشی و آزمون عملکرد پیوسته.