[Disruptive behaviour problems in childhood: studies on phenotypic heterogeneity and neurobiology from the Generation R Study].

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 multi-dimensionality 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 multi-dimensional 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.