Adolescent Firesetting as a Risk Marker for Adult Externalizing and Internalizing Problems: Analysis of a 40-Year Birth Cohort Study

Within the Christchurch Health and Development Study (N = 1,265), we examine the prevalence and continuity of firesetting across the life course and explore whether adolescent firesetting is a risk marker for adult internalizing and externalizing behaviors. Life course continuity of firesetting was low. Adolescent firesetting (3%) correlated with antisocial behaviors and adverse family circumstances. Independent of conduct disorder, adolescent firesetting showed limited associations with adulthood internalizing outcomes, but associated with most externalizing outcomes (e.g., cannabis use disorder, OR = 2.08, 95% CI = [1.14, 3.78]). Further adjustment for antisocial tendencies and family circumstances reduced associations; the largest effect to remain was for alcohol use disorder (OR = 2.08, 95% CI = [1.19, 3.63]). Therefore, for most externalizing behaviors, adolescent firesetting is a marker (i.e., indicates future risk), but not an independent risk marker (i.e., does not have independent specificity). For adolescents who set fires, clinical treatment should assess comorbid conduct disorder and family instability and consider a range of problematic outcomes.