Associations between early regulatory problems and long-term neurobiological and psychosocial outcomes

Early regulatory problems (RPs, i.e. problems with crying, sleeping and feeding), are associated with increased susceptibility to avoidant personality traits and peer relationship issues in adulthood. RPs have been linked to intrinsic functional connectivity changes within the allostatic-interoceptive system, notably involving the insula, which integrates sensory and interoceptive signals. The current study investigated whether early RPs and psychosocial outcomes in adulthood are associated with the insula morphology. Using data of the Bavarian Longitudinal Study, we analyzed individuals with RPs ( N = 47) and a matched never RPs group ( N = 121), who, in adulthood, underwent MRI and completed the Young Adult Self Report and Life Course Interview, to derive avoidant personality and peer relationship quality scores. RP group showed increased gyrification in the left insula when avoidant personality traits were included in the model. Importantly, individuals with both RPs and higher avoidant personality scores exhibited morphological insula differences. No significant associations were observed in cortical volume, thickness, or sulcal depth, or with peer relationship quality. Morphological differences were largest in individuals with persistent RPs. The findings highlight associations between early RPs and long-lasting neurobiological and psychosocial outcomes, providing important insights for the planning and development of targeted prevention and intervention strategies.