Linking childhood irritability to adolescent suicidality: Parent-adolescent and peer relationships as...

The irritability-suicidality link has been identified in extensive adolescent suicide research. Few studies, however, have investigated the mechanisms underlying this link within a developmental psychopathology framework. The present study aims to address this issue, with a consideration of contextual differences, by examining whether irritability observed at home and in school increases suicidal risk indirectly through dysfunctional parent-adolescent and peer relationships in a prospective cohort of 932 participants (53.0% girls; 54.6% Black, 25.2% White, 20.2% Mixed or Other race; from the United States). The general levels (i.e., random intercept, RI) of teacher-reported irritability across childhood (age 6-12) independently predicted mid- to late-adolescent suicidality (ages 16-18), whereas the parent RI and the interaction of these two RIs had limited predictive utility for suicidal risk. Poor relationships with parents and peers (age 14) partly mediated the prediction of suicidality from the parent and teacher RIs, respectively. These findings indicate that higher levels of teacher-reported irritability, irrespective of the levels of parent-reported irritability, place youth at greater risk for suicidality; dysfunctional parent-adolescent and peer relationships serve as possibly context-specific pathways from early irritability at home and in school, respectively, to later suicidality. Theoretical and clinical implications are discussed.