Denmark: In children aged 7 to 11 years, familial high risk (FHR) of schizophrenia, but not bipolar disorder, is tied to stable neurocognitive impairments, says a recent study. The findings of the study, published in JAMA Psychiatry warrant early attention to this group.
Findings from the cohort study suggest that neurocognitive maturation was comparable across groups of children at FHR of schizophrenia or bipolar disorder versus population-based control (PBC) from age 7 to 11 years. Children at FHR of schizophrenia compared with the PBC group showed widespread, stable, neurocognitive impairments during this period, children at FHR of bipolar disorder however showed no neurocognitive impairments. This implies distinct neurodevelopmental pathways in children at FHR of schizophrenia and bipolar disorder.

Neurocognitive impairments occur in children at FHR of bipolar disorder and schizophrenia. Studies on preadolescent developmental courses of neurocognition are crucial to describe shared and distinct neurodevelopmental pathways in these groups.
Against the above background, Christina Bruun Knudsen, Psychosis Research Unit, Aarhus University Hospital–Psychiatry, Aarhus, Denmark, and colleagues aimed to assess the development of specific neurocognitive functions from age 7 to 11 years in children at FHR of schizophrenia or bipolar disorder compared with children in a PBC group.
The Danish High Risk and Resilience Study is a prospective, longitudinal, cohort study that collected data from January 1, 2013, to January 31, 2016 (phase 1), and from March 1, 2017, to June 30, 2020 (phase 2). Data collection was done at 2 university hospitals in Denmark. Participants included 520 children at FHR of schizophrenia or bipolar disorder along with a PBC group matched with the group of children at FHR of schizophrenia by age, sex, and municipality.
Using validated tests of intelligence, attention, processing speed, memory, executive functioning, and verbal fluency neurocognitive functioning was assessed. Neurocognitive development from age 7 to 11 years was estimated using multilevel mixed-effects linear regression models with maximum likelihood estimation.
The findings of the study were as follows:
At 4-year follow-up, a total of 451 children (mean age; 11.9 years; 208 girls [46.1%]) underwent neurocognitive testing. There were a total of 170 children at FHR of schizophrenia (mean age, 12.0; 81 girls [47.7%]), 103 children at FHR of bipolar disorder (mean age, 11.9 years; 45 girls [43.7%]), and 178 children in the PBC group (mean age, 11.9 years; 82 girls [46.1%]).
At either age 7 or 11 years or at both assessments, 520 children participated in the neurocognitive assessment and were therefore included in the analyses. When correcting for multiple comparisons, no statistically significant time × group interactions were observed across the 3 groups.
Compared with the PBC group at 4-year follow-up, children at FHR of schizophrenia showed significant neurocognitive impairment in 7 of 24 neurocognitive measures (29.2%; Cohen d range, 0.29-0.37).
Compared with children at FHR of bipolar disorder, children at FHR of schizophrenia had significant neurocognitive impairment in 5 of 24 measures (20.8%; Cohen d range, 0.29-0.38).
Children at FHR of bipolar disorder and those in the PBC group did not differ significantly.
The researchers concluded, "results of this study indicate that FHR of schizophrenia, but not bipolar disorder, is associated with stable neurocognitive impairments in children aged 7 to 11 years, which warrants early attention toward this group."
Reference:
Knudsen CB, Hemager N, Greve AN, et al. Neurocognitive Development in Children at Familial High Risk of Schizophrenia or Bipolar Disorder. JAMA Psychiatry. Published online April 06, 2022. doi:10.1001/jamapsychiatry.2022.0465