Sex-specific pathways from early irritability trajectories to later suicidal ideations and behaviors: Findings from...

Previous studies have demonstrated that children with high irritability are at increased risk for suicidal ideations and behaviors. However, they have mostly relied on teacher reports and shown mixed findings regarding sex differences. We aimed to identify developmental trajectories of childhood irritability, test their direct and indirect (through psychopathology) associations with adolescent suicidal ideations and behaviors, and examine whether these associations differed by sex.

This study used five waves of data from the adolescent brain cognitive development (ABCD) Study (N = 4,583). Parents rated their children's irritability yearly from ages 9-10 to ages 11-12, internalizing (e.g. depression) and externalizing (e.g. aggression) symptoms at ages 12-13, and suicidal ideations and behaviors (SIBs) at ages 13-14 using the child behavior checklist. Subgroups of irritability trajectories were derived using growth mixture modeling. Path analysis was conducted to test the total, direct, and indirect pathways from irritability trajectories to SIBs through internalizing and externalizing symptoms, and sex differences in those paths.

Four irritability trajectories were identified: low-stable (73.01%), rising (12.04%), declining (10.28%), and high-stable (4.67%). Compared with the other trajectories, children on the high-stable irritability trajectory were at higher risk for suicidal ideations (β = .13, p < .001), directly (β = .03, p = .04) and indirectly through internalizing and externalizing (β = .04 and 0.05, respectively, p's < .001) symptoms. Sex differences emerged for the rising and declining trajectories: pathways to suicidal ideations were mainly mediated by internalizing symptoms in females and externalizing symptoms in males. Pathways from all irritability trajectories to suicidal behaviors were mediated by internalizing and externalizing symptoms and were stronger in females than males.

Distinct trajectories of parent-reported irritability in childhood are differentially associated with suicidal ideation and behavior in adolescence, with the high-stable trajectory conferring the greatest risk. Internalizing and externalizing symptoms play key mediating roles, with notable sex differences in children following rising and declining irritability trajectories. Females with high irritability at any time point in preadolescence were at particular risk for suicidal behaviors.