Tonic and phasic irritability in 6-year-old children: differential correlates and outcomes

Objective: Irritability is a common and clinically important problem in children and adolescents and a risk factor for later psychopathology and impairment. Irritability can manifest in both tonic (e.g., irritable, touchy mood) and phasic (e.g., temper outburst) forms, and recent studies of adolescents suggest that they predict different outcomes. However, no studies have examined whether tonic and phasic irritability are empirically distinguishable in 6-year-old children and whether they have distinct correlates and outcomes. Method: We utilized data from a longitudinal study of an unselected community sample of four hundred fifty-two 6-year-olds followed at 3-year intervals to age 15. We conducted confirmatory factor analysis (CFA) using relevant items from a diagnostic interview and several parent-report inventories. Results: The CFA identified dimensions that were consistent with tonic and phasic irritability. Tonic irritability was independently associated with concurrent parent-reported temperamental negative affectivity and internalizing and externalizing disorders at age 6 and predicted higher rates of internalizing psychopathology, and suicidal ideation, in adolescence. Phasic irritability was independently associated with concurrent parent-reported temperamental negative affectivity, surgency, and low effortful control, maladaptive parenting styles and practices, and externalizing disorders at age 6, and predicted higher rates of externalizing psychopathology in adolescence. Conclusions: Tonic and phasic irritability in 6-year-old children appear to be distinguishable constructs with different temperament and parenting correlates and psychopathological outcomes. Distinguishing these components has implications for research on the etiology and pathophysiology of irritability and developing effective treatments.