The role of behavioral inflexibility and impulsivity in explosive outbursts among youth with Tourette syndrome.

Several children living with Tourette syndrome (TS) also present with recurrent episodes of sudden and intense anger, which are known as explosive outbursts. Nevertheless, individual characteristics influencing the onset of such outbursts remain poorly understood. In adults, impulsivity has been found to be a risk factor for explosive outbursts, but there are no such data among children. Additionally, behavioral inflexibility, which is conceptualized as a pattern of rigid, inflexible behavior in situations where it would be beneficial to adapt one's behavior to external demands, constitutes a trigger for anger outbursts in other neurodevelopmental conditions. However, its role in TS has not been studied yet. Therefore, the aim of this study was to assess whether impulsivity and behavioral inflexibility were associated with explosive outbursts. Three hundred and seventeen (317) parents of children (aged 6-14, 74.8% male) living with TS completed a series of online questionnaires. Parents completed the Behavioral Inflexibility Scale (BIS), the short-version of the UPPS-P Impulsivity Inventory, and the Rage Attack Questionnaire-Revised (RAQ-R) to assess behavioral inflexibility, impulsivity, and explosive outbursts, respectively. Parents also reported on socio-demographic and clinical characteristics of their child. Parent-rated impulsivity and behavioral inflexibility were significantly associated with explosive outbursts, as assessed with the RAQ-R. However, their interaction was not a significant predictor of explosive outbursts. Exploratory analyses also identified that several clinical characteristics, including tic severity and specific co-occurring conditions such as internalizing disorders, learning disorders, and sleep problems, were associated with explosive outbursts. Our results revealed that behavioral inflexibility, impulsivity, as well as several clinical characteristics were risk factors for explosive outbursts. Explosive outbursts are highly detrimental to the individual and familial functioning. Therefore, identifying risk factors for such outbursts is important given that it may lead to new targets for interventions aiming to decrease the frequency and intensity of explosive outbursts.