Changes in Early Childhood Irritability and Its Association With Depressive Symptoms and Self-Harm During Adolescence in a Nationally Representative United Kingdom Birth Cohort

ObjectiveTo investigate longitudinal associations between changes in early childhood irritability, and depressive symptoms and self-harm at 14 years.MethodWe used data from 7,225 children in a UK-based general population birth-cohort. Childhood irritability was measured at 3, 5 and 7 years using four items from two questionnaires (Children’s Social Behaviour Questionnaire; CSBQ and Strengths and Difficulties Questionnaire; SDQ). Participants reported depressive symptoms via the short Mood and Feelings Questionnaire (sMFQ) and self-harm via a single-item question, at 14 years. We used multilevel models to calculate within-child change in irritability between 3-7 years and examined associations between irritability, and depressive symptoms and self-harm at 14 using linear and logistic regression models respectively. We adjusted for child and family sociodemographic/economic characteristics, mental health difficulties and child cognitive development.ResultsIrritability at 5 and 7 years was positively associated with depressive symptoms and self-harm at age 14 years. Irritability which remained high between 3-7 years was associated with depressive symptoms and self-harm at 14 years in unadjusted (depressive symptoms: ß Coef. 0.22, 95%CI 0.08-0.37, p=0.003; self-harm: OR 1.09 95%CI 1.01-1.16, p=0.019) and adjusted models (depressive symptoms: ß Coef. 0.31, 95%CI 0.17-0.45, p<0.001; self-harm: OR 1.12, 95%CI 1.0.4-1.19, p=0.004). Results were similar in imputed samples.ConclusionChildren with irritability which remains high between 3-7 years are more likely to report higher depressive symptoms and self-harm during adolescence. These findings support early intervention for children with high irritability and universal interventions in managing irritability for parents of pre-school children.