Compulsivity and impulsivity traits linked to attenuated developmental frontstriatal myelination trajectories

Abstract

A transition from adolescence into adulthood corresponds to a period where rapid brain development coincides with an enhanced incidence of psychiatric disorder. The precise developmental brain changes that account for this emergent psychiatric symptomatology remain obscure. Capitalising on a unique longitudinal dataset, that includes in-vivo myelin-sensitive magnetization transfer (MT) MRI, we show that coming of age is characterised by brain-wide growth in MT, within both gray matter and adjacent juxta-cortical white matter. In this healthy population the expression of common developmental traits, namely compulsivity and impulsivity, are tied to a reduced unfolding of these MT trajectories in fronto-striatal regions. This reduction is most marked in dorsomedial and dorsolateral frontal structures for compulsivity, and in lateral and medial frontal areas for impulsivity. The findings highlight a brain developmental linkage for compulsivity and impulsivity is evident in regionally specific reduced unfolding of MT-related myelination.