Disruptive behaviour problems in childhood: Studies on phenotypic heterogeneity and neurobiology from the Generation R Study Disruptieve gedragsproblemen op de kinderleeftijd: Studies naar fenotypische heterogeniteit en neurobiologie in de Generation R Studie

BACKGROUND Disruptive behaviour problems in childhood are strongly predictive of physical and mental health problems and criminality. A better understanding of the development of children with disruptive behaviour problems will help improve our understanding of later severe mental illnesses. AIM To gain insights into the neurodevelopment of children with disruptive behaviour problems. Here, we focused on their phenotypic heterogeneity and the underlying neurobiological substrates of disruptive behaviour problems. METHOD All studies described in the discussed thesis were embedded in the Generation R Study, a prospective population-based birth cohort from Rotterdam, the Netherlands. Data were, amongst others, collected through multi-informant questionnaires and neuroimaging. RESULTS Empirically obtained dimensions of disruptive behaviour problems included oppositional/disobedient behaviour, physical aggression, irritability, and delinquent behaviour. Less white matter microstructure was related to more delinquent behaviour, taking into account the multidimensionality of disruptive behaviour problems. Callous traits were characterised by widespread macro- and microstructural differences across the brain. CONCLUSION These studies have shown that disruptive behaviour problems in childhood can be best conceptualized as a complex multi-dimensional phenotype. Taking into account this multidimensional heterogeneity has proven beneficial for the finding of underlying neurobiological mechanisms. Considering disruptive behaviour problems are predictive of later severe mental disorders, it is paramount to acknowledge the neurodevelopmental perspective on behaviour problems.