Replicability of the neuroanatomical correlates of impulsive personality traits in the ABCD study

While the neuroanatomical correlates of impulsivity in youths have been examined, there is little research on whether those correlates are consistent across childhood/adolescence. The current study uses data from the age 11/12 (N = 7083) visit of the Adolescent Brain Cognitive Development (ABCD) Study to investigate the replicability of the neuroanatomical correlates of impulsive personality traits identified at age 9/10. Neuroanatomy was measured using structural and diffusion magnetic resonance imaging and impulsive personality was measured using the UPPS-P Impulsive Behavior Scale. Replicability was quantified using the Open Science Foundation replication criteria, intraclass correlations, and elastic net regression modeling to make predictions across timepoints. Replicability was highly variable among traits: the neuroanatomical correlates of positive urgency showed substantial similarity between ages 9/10 and 11/12, negative urgency and sensation seeking, showed moderate similarity across ages, and (lack of) premeditation and perseverance showed substantial dissimilarity across ages. In all cases, effect sizes were small. These findings suggest that, even for studies with large samples sizes and the same participant pool, the replicability of brain-behavior correlations cannot be assumed. However, they also highlight an array of neuroanatomical structures that may be important to impulsive personality traits across development from childhood into adolescence.