Impairments in verbal and spatial working memory as a predictor of psychopathology in offspring of patients with schizophrenia or bipolar disorder

Abstract

Schizophrenia offspring (SZo) and bipolar disorder offspring (BDo) are at an increased risk for developing psychopathology. To recognize at-risk individuals early, more insight into the vulnerability markers of both disorders is needed. Research suggests that verbal and spatial working memory could be cognitive markers for developing schizophrenia or bipolar disorder. The current study investigated whether SZo and BDo differed in verbal and spatial working memory compared to healthy controls (HCo). In addition, it was examined whether verbal and spatial working memory performance could serve as a predictor for (sub)clinical psychotic, depressive or manic symptoms. This study was part of the longitudinal Dutch Bipolar and Schizophrenia Offspring Study (DBSOS). At baseline, the sample included 200 subjects (age M=13.10; SD=2.42). The Backward Digit Span and Spatial Temporal Span measured verbal and spatial working memory at baseline and follow-up. The Comprehensive Assessment of At-Risk Mental States (CAARMS) and the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version (K-SADS-PL) were administered at follow-up, to measure the presence of psychotic, depressive and manic symptoms. Results revealed no significant differences in verbal and spatial working memory between SZo, BDo, and HCo. In addition, only manic symptoms could be predicted by spatial working memory performance. The findings implicate that these possible cognitive markers of bipolar disorder and schizophrenia are not visible at an early age. Future research should explore the presence of working memory difference at a later stadium of the disorders.