The Role of Negative Urgency in Impulsivity and Anxiety

Abstract

Clinically significant anxiety and impulsivity are both highly prevalent and impair functioning in multiple domains. Historically, trait impulsivity has been considered the opposite of anxious avoidance, despite co-occurring presentations of anxiety and impulsivity across internalizing and externalizing disorder spectrums. Due to broad conceptualizations of impulsive behavior, it remains unclear whether anxiety could be positively associated with global impulsivity or specific facets of impulsivity. Negative urgency, or rash behavior that specifically occurs during negative emotional states, may provide common ground to examine the overlap between high anxiety and high impulsivity. Prior literature suggests that negative urgency is related to patterns of behavioral (e.g. experiential avoidance) and neural processes often associated with both anxiety and global impulsivity. This dissertation explored the role of negative urgency within relationships between anxiety, global impulsivity, experiential avoidance, and prefrontal cortex (PFC) activation. In our first study, we examined self-report data collected from adult participants (n = 589) to test the indirect effect of anxiety on experiential avoidance through both negative urgency and global impulsivity. Contrary to our hypotheses, we found that there was no significant indirect effect of anxiety on experiential avoidance through negative urgency alone. However, follow-up analyses including data-driven factors of impulsivity revealed significant positive indirect effects of anxiety on experiential avoidance through emotion-based impulsivity (i.e., negative and positive urgency) and hyperactivity. There was also a significant negative indirect effect of anxiety on experiential avoidance through a non-planning impulsivity factor. This study helps to inform future studies interrogating links between anxious avoidance and specific dimensions of impulsivity. In our second study, we examined shared and distinct patterns of activation in the PFC associated with inhibitory control during emotional interference and motor inhibition tasks. Pre-adolescents (ages 9-10; n = 2264) from the Adolescent Brain Cognitive Development (ABCD) Study completed the Emotional N-Back (EN-Back) Task as a probe of emotional interference and the Stop Signal Task (SST) as a probe of motor inhibition during brain scanning. A conjunction analysis revealed shared activation across tasks in the inferior frontal gyrus (IFG); activation specific to the EN-Back task in the middle frontal gyrus (MFG); and activation specific to the SST in the dorsal anterior cingulate cortex (dACC) and dorsolateral PFC (dlPFC). These findings support distinctions in PFC involvement in emotional and non-emotional inhibitory control and suggest neural targets for future analyses using the ABCD dataset. In our third study, we examined links between task-specific brain function identified in Study 2 and measures of anxiety and impulsivity. We aimed to explore the role of negative urgency in relationships between anxiety, global impulsivity, and PFC function. We found a positive relationship between anxiety and global impulsivity and a significant direct effect of anxiety on MFG activation during emotional interference. We found no significant indirect effects between anxiety, impulsivity, negative urgency, and PFC function. Considerations surrounding data characteristics and future analyses examining relationships between clinical symptoms and PFC function in developmental samples are discussed. These findings highlight the importance of investigating links between anxiety and dimensions of impulsivity and provide support for further research interrogating nuances in behavioral and mechanistic relationships between these constructs. This research has important implications for the reclassification of diagnostic categories that may inform prevention and treatment efforts.