According to the results of a study published in JAMA Psychiatry, general cognition and psychopathology in adolescents were shown to be heritable through similar pathways and to share the brain white matter characteristics of crossing fibers in the frontotemporal region.
In this cross-sectional study, 729 children and adolescents (mean [SD] age 15.1 [3.3]; age range 8-22; 46% female) from the Philadelphia Neurodevelopmental Cohort were enrolled and underwent diffusion magnetic resonance imaging (MRI) brain scans. Behavioral phenotypes, including psychopathology, were assessed by a computerized test battery. A genome-wide complex trait analysis was performed to evaluate the heritability of psychopathology and cognition. In addition, associations between MRI findings and general psychopathology and cognition were evaluated.
Linked independent component mapping revealed a significant association between white matter patterns and general cognitive factors (P <.001) and psychopathology (P <.001). For both traits, the association was strongly driven by the degree of crossing fibers in frontotemporal connections, particularly in the uncinate fasciculus.
In univariate analyses, the white matter brain architecture of crossing fibers in frontotemporal connections was shown to be more expressed in participants with better cognitive performance (eg, higher Penn Verbal Reasoning Test scores or Wide Range Assessment Test Scores) and less expressed in participants with more severe general psychopathology (eg, agoraphobia or post-traumatic stress disorder).
Cognition and psychopathology were negatively correlated in genetic analyses. Shared single nucleotide polymorphisms were responsible for 18% of the individual differences in general cognitive factors (P =.01) and 16% of the differences in general psychopathology (P =.05).
“The results of this study point to limbic temporo-amygdala-orbitofrontal pathways as a candidate transdiagnostic brain phenotype in psychiatric disorder,” the researchers wrote. “Importantly, the present findings show that such abnormalities are present also in youth who do not have a diagnosis but are at risk for psychiatric disease.”
Alnæs D, Kaufmann T, Doan NT, et al. Association of heritable cognitive ability and psychopathology with white matter properties in children and adolescents [published online January 24, 2018]. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2017.4277