The executive control of attention differentiates patients with schizophrenia, their first-degree relatives and healthy controls

Attentional and executive impairments have been reported in patients with schizophrenia and in their healthy first-degree relatives. However, its nature remains unclear and discrepancies between studies have been observed. These might be due to differences in the clinical severity of the illness or in sociodemographic factors. The objective of the present work was to explore the efficiency of three attention networks: alerting, orienting and executive control (conflict inhibition) defined anatomically, using patients, their relatives and controls, assessing the possibility to use them as endophenotypes. We used three tests, the Attention Network Test (ANT), the Wisconsin Card Sorting Test (WCST) and the Stroop Test, and compared 52 patients with schizophrenia, 55 of their first-degree relatives and 53 unrelated healthy controls, taking into account demographic variables (age, sex and years of education) and clinical symptoms of schizophrenia. Patients had a longer overall mean reaction-time (p < 0.001), and took longer to resolve the ANT conflict (ANTc) (p = 0.04) than the control group. In the schizophrenia group, the SSPI disorganization score was significantly correlated to the ANTc performance. Additionally, first-degree relatives of patients with schizophrenia also performed significantly worse than controls in attention performance test. Our findings support a specific deficit in executive control of attention in patients with schizophrenia. This deficit was shown to be correlated with the intensity of the disorganization score in patients. Relative presented an intermediate phenotype between patients and controls; the ANT reaction time (but not the ANTc) may thus be considered as possible endophenotype marker for schizophrenia.