Individual-level deviations from normative brain morphology in violence, psychosis, and psychopathy

Abstract

BackgroundNeuroimaging research has shown brain morphological abnormalities associated with violence and psychosis, but individual differences are substantial and results not consistent across studies. Recently developed normative modeling of brain MRI-features provides a possibility to parse this heterogeneity by mapping inter-individual brain characteristics, which has not yet been explored in forensic psychiatry.MethodsWe explored brain heterogeneity in persons with a history of severe violence with or without a schizophrenia spectrum disorder (HoV, n=58), non-violent patients with schizophrenia spectrum disorders (SSD-NV, n=138), and healthy non-violent controls (HC) from lifetime normative trajectories of cortical thickness, surface area, and subcortical volumes. Normative models were based on Freesurfer derived regions of interest from 58,836 individuals (ages 2-100) from 82 sites. Group differences and associations between brain deviations and psychopathy traits (PCL-R scores) were investigated.ResultsAcross groups, we found an overall heterogeneous pattern of individual-level deviations, with a significantly higher frequency of extreme negative deviations in HoV (p=.020,d=.31) and SSD-NV (p=.019,d=.48), than HC. Group differences were mostly present in subcortical volumes and cortical area, but not thickness, with significant regional group-level differences within the subcallosal and insular cortices, and the cerebellum, and no significant associations to psychopathy traits.ConclusionBy applying normative modeling, this proof-of-concept study demonstrates the heterogeneous pattern of brain morphometry deviations associated with violence and psychosis. While the results warrant replication, studies addressing individual brain deviations may contribute to improved understanding of the complex underpinnings of violence in forensic psychiatry.