Dimensions of Childhood Irritability and Predictions of Adolescent Psychopathology

• In Event: Poster Session 10
  In Poster Session: PS 10 Topic - Developmental Psychopathology

Abstract

Introduction: Youth psychopathology, including depression, anxiety, and attention-deficit/ hyperactivity disorder, are highly prevalent, frequently have a childhood onset, and increase acutely in adolescence. These problems incur significant public health, educational, and economic costs (Dieleman et al., 2016). Although irritability is a replicated risk factor for both internalizing and externalizing domains, irritability consists of separable facets (i.e., tonic – grouchy mood vs phasic – behavioral outbursts) with differential predictive validity and clinical correlates (e.g., comorbidity) (Copeland et al., 2015; Moore et al., 2019). Moreover, potential moderators are scantly considered. Preliminary evidence suggests that irritability differentially predicts outcomes in boys versus girls (Humphreys et al., 2019). However, this study treated irritability unidimensionally, thus obfuscating potential sex differences. The current study aims to test childhood irritability dimensions by sex interactions, with respect to predictions of adolescent internalizing and externalizing problems. I hypothesize that phasic and tonic irritability will positively predict internalizing problems in girls whereas tonic irritability will specifically predict elevated internalizing problems in boys. I also hypothesize that phasic irritability will significantly predict externalizing problems specifically in boys.
Methods: At baseline, 232 participants (ages 5-10, 45% non-Caucasian) with and without ADHD (50% meeting ADHD diagnosis) were recruited for a lab-based study of socio-emotional development and followed prospectively across six years. Separate, but parallel Wave 2 (age 7-12, n=206) and Wave 3 (ages 9-15, n=183) follow-up assessments were performed. Multiple methods and informants were prioritized for key constructs: parents completed the Diagnostic Interview Schedule for Children (DISC-IV) and Disruptive Behavior Disorder (DBD) rating scale; teachers completed the DBD. Tonic irritability was derived from the DISC and DBD (i.e., touchy/easily annoyed/irritable, angry/resentful) whereas phasic irritability was estimated from a single item (i.e., temper tantrums/angry outbursts). Wave 3 psychopathology was assessed using parent ratings on the Child Behavior Checklist. Covariates included race-ethnicity, baseline age and ADHD symptoms, and baseline levels of Wave 3 psychopathology outcome being predicted.
Results: The Wave 1 tonic irritability x sex interaction significantly predicted Wave 3 CBCL anxious-depressed (β=-1.33,t=-1.98,p=0.049); post-hoc probing of the interaction revealed that tonic irritability significantly predicted adolescent anxiety problems specifically in girls (β=1.14,t=1.97,p=0.05). Tonic irritability x sex interaction also significantly predicted CBCL externalizing problems (β=-3.31,t=-2.62,p=0.0098); post-hoc probing revealed that tonic irritability significantly predicted adolescent externalizing problems in girls (β=2.27,t=2.00,p=0.047). Finally, phasic irritability x sex interaction also significantly predicted CBCL withdrawn/depressed (β=-1.62,t=-2.26,p=0.025); post-hoc probing revealed that phasic irritability significantly predicted adolescent depressive problems in boys (β=-0.81,t=-1.99,p=0.048). Regardless of sex, tonic irritability significantly predicted Wave 3 CBCL anxiety disorder (β=0.77,t=2.07,p=0.040)and phasic irritability significantly predicted CBCL externalizing problems (β=5.38,t=2.88,p=0.0046).
Discussion: To review, the current project tested the predictive utility of irritability dimensions (i.e., tonic and phasic), derived from multiple measures/informants during childhood, on adolescent internalizing and externalizing psychopathology, controlling for demographic factors as well as baseline ADHD and internalizing/externalizing psychopathology. Given the interest in irritability and its centrality to the DMDD diagnosis in DSM-5, it is crucial to evaluate its predictive utility. Preliminary results suggest that the underlying dimensions of irritability (i.e., tonic vs phasic) differentially predict outcomes in boys and girls.

Authors

• Felix So, University of California - Los Angeles
  Presenting Author

• Hanna Nguyen
  Non-Presenting Author

• Steve Lee, University of California, Los Angeles
  Non-Presenting Author