ABSTRACT: Conduct disorder (CD) is one of the most prevalent and debilitating psychiatric disorders impacting our youth. Unfortunately, the effects of CD are not limited to these early years. Youth with CD are more likely to develop lifelong mental and physical health problems, which is why CD is responsible for 5.75 million years of healthy life lost. There is mixed evidence supporting the effectiveness of treatment for CD, and this may be because youth with CD have differing etiological mechanisms. Research has shown that there is heterogeneity among youth with CD, with a subgroup of CD youth displaying more severe behavioral and personality symptoms, called callous-unemotional (CU) traits. CU traits is a specifier for CD that designates a high-risk group of youth who engage in chronic violence and criminal behavior, placing a significant burden on families and society. The key distinction is that these youth show distinct personality symptoms that current CD interventions are not equipped to treat, such as callousness towards others, lack of empathy and guilt for their harmful behaviors, and shallow/diminished affect. Understanding the mechanisms behind CU traits is essential for equipping interventions with the knowledge needed to employ a targeted approach for treating CU traits. Longstanding theories suggest that fearlessness is a key mechanism in the development of CU traits. However, biological evidence supporting the association between CU traits and fearlessness is deficient, and the current state of this examination has been restricted because of ecological validity. We will examine the association between fear and CU traits in youth (13-17 years) with CD by measuring sympathetic (pre-ejection period) and parasympathetic nervous system reactivity (respiratory sinus arrhythmia) during immersion in cutting edge virtual reality (VR) fear induction. We will concurrently apply facial electromyography to assess levels of positive and negative valence. We will also determine sex differences in these associations, as well as provide evidence of how biological fear profiles contribute to the stability of CU traits over 12 months during the adolescent period. The potential benefits of the proposal are high. Based on our pilot data, we will test our hypothesis that youth with CU traits will display a unique biological profile to fear that cannot be explained by fearlessness, and these associations are sex-specific. Confirming this finding in youth with CD may lead to reshaping prior developmental theories of CU traits that could lead to improved screening and more favorable gender-responsive treatment strategies for our youth.

Project Narrative: Research on CD and CU traits has increased greatly in recent years, yet, the mechanisms underlying CU traits in this high-risk population remain poorly understood. Our research strategy integrates cutting edge virtual reality fear induction technology while measuring multiple physiological indices in youth with CD to differentiate boys and girls with varying levels of CU traits. The outcomes from this research will provide a more accurate physiological fear profile for youth with CU traits, which will lead to improvements in gender-responsive intervention strategies, with the ultimate aim of early detection and prevention.