Abstract
Irritability is associated with an array of deleterious outcomes. Yet research examining its predictors over time is limited. The present study addresses this gap by applying latent growth curve modeling (LGCM) to a nationally representative longitudinal dataset from the Adolescent Brain Cognitive Development (ABCD) study (N = 11,720, 47.9% female).
Confirmatory factor analysis and second-order LGCM analyses were used to model irritability across early adolescence (ages 9-13) using three parent-report indicators collected at four timepoints. Baseline cognitive flexibility and inhibitory control were examined as predictors of growth parameters. Conditional models were examined with and without covariates of attention-deficit/hyperactivity disorder (ADHD) symptoms and biological sex.
The latent factor for irritability fit the data well. The best-fitting unconditional model showed that there was a modest but significant decline in irritability. However, not all youths followed this average trajectory. In conditional models, higher baseline levels of cognitive flexibility and inhibitory control predicted lower baseline levels of irritability, but contrary to our hypotheses, baseline cognitive flexibility and inhibitory control predicted a faster decline in irritability over time. These effects of cognitive variables on latent intercepts and slopes were attenuated to non-significance when covariates were added to the model.
The present study is the first to characterize irritability’s average change across early adolescence. Our results are consistent with the idea that irritable youth often develop their cognitive abilities while responding to frustrating situations, leading to a decrease over time. Of note, these effects were no longer significant after accounting for covariates, suggesting that other variables may be confounding associations. Future work should aim to measure cognitive flexibility and inhibitory control under emotional contexts, such as frustration, as this may be when these abilities are most salient for irritable youth.