The Tonic and Phasic Irritability Scale (TAPIS): Concurrent and short-term predictive validity in early childhood

Irritability comprises two related but distinct dimensions: tonic irritability, reflecting persistently angry mood, and phasic irritability, reflecting temper outbursts. Distinguishing these forms is important given their differential associations with psychopathology. The Tonic and Phasic Irritability Scale (TAPIS) is the first measure designed to assess these constructs. This study evaluated the structural and external validity of the TAPIS in young children.

Participants were 213 parents of 5-6-year-old children (50% female), oversampled for high irritability. At screening, caregivers completed the TAPIS and other irritability and impairment measures to determine eligibility. Eligible families completed a full evaluation an average of 2.76 months later (SD = 2.84; range = 0.07-21.28 months), including parent-report measures of child psychopathology, temperament, and parenting.

The TAPIS demonstrated a two-factor structure (robust CFI = 0.92, TLI = 0.91, SRMR = 0.03) with excellent internal consistency (α = .95 tonic; 0.94 phasic). Both dimensions were associated with established irritability measures and impairment. When modeled simultaneously, phasic irritability uniquely predicted multiple irritability indicators and impairment across domains, whereas tonic irritability uniquely predicted caregiver-reported irritability, temper loss, and child-domain impairment. TAPIS demonstrated incremental validity in predicting impairment beyond most comparison measures. Prospectively, tonic irritability predicted affective, anxiety, depressive, ADHD, and oppositional symptoms and higher negative affect, whereas phasic irritability predicted oppositional and conduct symptoms and lower effortful control.

Findings support the reliability and validity of the TAPIS in early school-age children and provide evidence for the short-term predictive validity of tonic and phasic irritability dimensions.