Impaired processing speed and attention in first-episode drug naive schizophrenia with deficit syndrome

Abstract

Although first-episode drug naive patients with schizophrenia are known to show cognitive impairment, the cognitive performances of these patients, who suffer deficit syndrome, compared with those who suffer non-deficit syndrome is undetermined. The aim of this study was to compare cognitive performances in first-episode drug-naive schizophrenia with deficit syndrome or non-deficit syndrome. First-episode drug naive patients (n=49) and medicated patients (n=108) with schizophrenia, and age, sex, and education matched healthy controls (n=57 for the first-episode group, and n=128 for the medicated group) were enrolled. Patients were divided into deficit or non-deficit syndrome groups, using the Schedule for Deficit Syndrome. Cognitive performance was assessed using the CogState computerized cognitive battery. All cognitive domains in first-episode drug naive and medicated patients showed significant impairment compared with their respective control groups. Furthermore, cognitive performance in first-episode drug naive patients was significantly worse than in medicated patients. Interestingly, the cognitive performance markers of processing speed and attention, in first-episode drug naive patients with deficit syndrome, were both significantly worse than in equivalent patients without deficit syndrome. In contrast, no differences in cognitive performance were found between the two groups of medicated patients. In conclusion, this study found that first-episode drug naive schizophrenia with deficit syndrome showed significantly impaired processing speed and attention, compared with patients with non-deficit syndrome. These findings highlight processing speed and attention as potential targets for pharmacological and psychosocial interventions in first-episode schizophrenia with deficit syndrome, since these domains are associated with social outcomes.