Impact of Irritability and Impulsive Aggressive Behavior on Impairment and Social Functioning in Youth with Cyclothymic Disorder

Objective: Research on adults with cyclothymic disorder (CycD) suggests that irritability and impulsive aggression (IA) are highly prevalent among this population. Less is known about whether these behaviors might also distinguish youth with CycD from youth without CycD. Additionally, little is known about how irritability and IA relate to one another, and whether they are associated with different outcomes. This study aimed to compare irritability and IA across diagnostic subtypes to determine whether CycD is uniquely associated with these behaviors, and to assess how irritability and IA relate to youth social and general functioning. Methods: Participants (n=459), 11-18 years of age, were recruited from an urban community mental health center and an academic outpatient clinic; 25 had a diagnosis of CycD. Youth and caregivers completed measures of IA and irritability. Youth and caregivers also completed an assessment of youth friendship quality. Clinical interviewers assessed youth social, family, and school functioning. Results: Youth with CycD had higher scores on measures of irritability and IA than youth with nonbipolar disorders, but scores were not different from other youth with bipolar spectrum disorders. Measures of irritability and IA were correlated, but represented distinct constructs. Regression analyses indicated that irritability was related to friendship quality (p<0.005). Both IA and irritability were related to social impairment (ps<0.05-0.0005) and Child Global Assessment Scale (C-GAS) scores (ps=0.05-0.005). CycD diagnosis was associated with poorer caregiver-rated friendship quality and social functioning (ps < 0.05). Conclusions: We found that irritability and aggression were more severe among youth with CycD than among youth with nonbipolar diagnoses, but did not differ across bipolar disorder subtypes. Among youth seeking treatment for mental illness, irritability and IA are prevalent and nonspecific. Irritability and IA were uniquely related to our outcomes of social and general functioning, suggesting that it is worthwhile to assess each separately, in order to broaden our understanding of the characteristics and correlates of each.