Neuropsychological characteristics of child and adolescent offspring of patients with schizophrenia or bipolar disorder

Abstract

Background: Schizophrenia (SZ) and bipolar disorder (BD) are considered neurobiological disorders which share some clinical, cognitive and neuroimaging characteristics. Studying child and adolescent offspring of patients diagnosed with bipolar disorder (BDoff) or schizophrenia (SZoff) is regarded as a reliable method for investigating early alterations and vulnerability factors for these disorders. This study compares the neuropsychological characteristics of SZoff, BDoff and a community control offspring group (CC) with the aim of examining shared and differential cognitive characteristics among groups. Methods: 41 SZoff, 90 BDoff and 107 CCwere recruited. Theywere all assessedwith a complete neuropsychological batterywhich included intelligence quotient,working memory (WM), processing speed, verbalmemory and learning, visual memory, executive functions and sustained attention. Results: SZoff and BDoff showed worse performance in some cognitive areas compared with CC. Some of these difficulties (visual memory) were common to both offspring groups, whereas others, such as verbal learning andWM in SZoff or PSI in BDoff, were group-specific. Conclusions: The cognitive difficulties in visualmemory shown by both the SZoff and BDoff groups might point to a common endophenotype in the two disorders. Difficulties in other cognitive functions would be specific depending on the family diagnosis.