Distinct Characteristics in Children at Risk for Schizophrenia vs Bipolar Disorder
Subtle cognitive impairments of sustained attention are often present in children who go on to develop schizophrenia.
Sustained attention and interference control deficits are evident in children with a familial high risk for schizophrenia at age 7 but are largely absent in children with a familial high risk for bipolar disorder, according to the results of a Danish observational cohort study published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
Individuals with schizophrenia or bipolar disorder display cognitive impairments, but those found in individuals with schizophrenia are likely to be more severe. Subtle cognitive impairments of sustained attention are often present in children who go on to develop schizophrenia. Furthermore, whereas poor academic performance during childhood often precedes schizophrenia, children who go on to develop bipolar disorder may exhibit either poor or excellent academic performance.
Birgitte Klee Burton, MD, PhD, of the Child and Adolescent Mental Health Centre, Mental Health Services Capital Region, Research Unit at Copenhagen University Hospital in Copenhagen, Denmark, and The Lundbeck Foundation Initiative for Integrative Psychiatric Research (iPSYCH) in Aarhus, Denmark, and colleagues identified an observational cohort through Danish registries of 522 children who were 7 years old with no, one, or two parents with a diagnosis of schizophrenia or bipolar disorder. They assessed sustained attention and interference control using Conners' Continuous Performance Test II and a modified Eriksen flanker task.
Children with a familial high risk for schizophrenia showed evidence of deficits in sustained attention and subtle deficits in interference control as compared with both control children and children with a familial high risk for bipolar disorder. In contrast, children with a familial high risk for bipolar disorder exhibited comparable ability on both measures to control children except for a lower accuracy on interference control.
The authors suggest that the findings of this study contribute to the understanding of the neurodevelopmental cognitive vulnerability in middle childhood for the children of individuals with either schizophrenia or bipolar disorder. They also argue that their results suggest that deficits of sustained attention may be considered as potential endophenotypes for schizophrenia. Finally, they note that the results show a positive correlation between deficits in sustained attention and motor abilities, which they believe could reflect the interaction of the motor and cognitive systems during development.
Burton BK, Vangkilde S, Petersen A, et al. Sustained attention and interference control among 7-year-old children with a familial high risk of schizophrenia or bipolar disorder—a nationwide observational cohort study. Biol Psychiatry Cogn Neurosci Neuroimaging. 2018. doi:10.1016/j.bpsc.2018.04.012