Summary: Disruptions in fiber tracts connecting brain regions associated with cognitive behavior and emotional regulation in teens appear to be linked to higher risk of psychiatric disorders, researchers report.
Source: University of Oslo.
Adolescence is a period for individual growth and opportunities, but it also coincides with the emergence of many mental disorders. In a study that was recently published in JAMA Psychiatry, Norwegian researchers revealed that the pathways between brain regions are associated with early signs of mental illness in youth.
The researchers analyzed a wide range of clinical, cognitive, and genetic data from more than 6000 children and adolescents. They derived a score of general cognitive ability as well as early signs of psychiatric symptoms for each individual, and analyzed images of pathways in the brain of more than 700 of the participants using advanced machine learning techniques.
The study showed that the score of preclinical psychiatric symptoms was heritable and associated with disruption of specific pathways in the brain.
“We found that disruption of fiber tracts connecting brain regions involved in emotional regulation and complex cognitive behavior was linked to higher levels of psychiatric symptoms. Although follow-up studies are needed, this suggests that aberrant connections between specific brain regions present at a young age may be associated with increased susceptibility for mental illness later in life, says lead author Dag Alnæs.
Even though mental disorders typically manifest in adolescence and early adulthood, the vulnerability for developing disease may be present before any overt symptoms arise. “The ultimate goal is to be able to predict which individuals are at risk before clinical symptoms appear”, associate professor Lars T. Westlye says. “Advanced brain imaging has been proposed to represent one promising approach for such early detection. However, at present there is no robust brain imaging marker that allows us to identify single individuals at risk with any clinically relevant certainty, but our study is one of several recent attempts to provide a first step towards this goal”.
The study is a collaboration between the Norwegian Centre for Mental Disorders Research (NORMENT) at the University of Oslo and Oslo University Hospital, and the Department of Psychology at the University of Oslo in Norway.
Source: University of Oslo
Publisher: Organized by NeuroscienceNews.com.
Image Source: NeuroscienceNews.com image is credited to the researchers.
Original Research: Abstract for “Association of Heritable Cognitive Ability and Psychopathology With White Matter Properties in Children and Adolescents” by Alnæs D, Kaufmann T, Doan NT, Córdova-Palomera A, Wang Y, Bettella F, Moberget T, Andreassen OA, Westlye LT in JAMA Psychiatry. Published March 2018.
Association of Heritable Cognitive Ability and Psychopathology With White Matter Properties in Children and Adolescents
Importance Many mental disorders emerge during adolescence, which may reflect a cost of the potential for brain plasticity offered during this period. Brain dysconnectivity has been proposed as a common factor across diagnostic categories.
Objective To investigate the hypothesis that brain dysconnectivity is a transdiagnostic phenotype in adolescence with increased susceptibility and symptoms of psychiatric disease.
Design, Setting, and Participants We investigated clinical symptoms as well as cognitive function in 6487 individuals aged 8 to 21 years from November 1, 2009, to November 30, 2011, in the Philadelphia Neurodevelopmental Cohort and analyzed diffusion magnetic resonance imaging brain scans for 748 of the participants.
Main Outcomes and Measures Independent component analysis was used to derive dimensional psychopathology scores, and genome-wide complex trait analysis was used to estimate its heritability. Multimodal fusion simultaneously modeled contributions of the diffusion magnetic resonance imaging metrics fractional anisotropy, mean diffusivity, radial diffusivity, L1 (the principal diffusion tensor imaging eigen value), mode of anisotropy, as well as dominant and secondary fiber orientations, and structural connectivity density, and their association with general psychopathology and cognition.
Results Machine learning with 10-fold cross-validation and permutation testing in 729 individuals (aged 8 to 22 years; mean [SD] age, 15.1 [3.3] years; 343 females [46%]) revealed significant association with general psychopathology levels (r = 0.24, P < .001) and cognition (r = 0.39, P < .001). A brain white matter pattern reflecting frontotemporal connectivity and crossing fibers in the uncinate fasciculus was the most associated feature for both traits. Univariate analysis across a range of clinical domains and cognitive test scores confirmed its transdiagnostic importance. Both the general psychopathology (16%; SE, 0.095; P = .05) and cognitive (18%; SE, 0.09; P = .01) factor were heritable and showed a negative genetic correlation.
Conclusion and relevance Dimensional and heritable general cognitive and psychopathology factors are associated with specific patterns of white matter properties, suggesting that dysconnectivity is a transdiagnostic brain-based phenotype in individuals with increased susceptibility and symptoms of psychiatric disorders.