Aggression and cardiovascular response in children

Physiological stress reactivity and physical and relational aggression: The moderating roles of victimization, type of stressor, and child gender

The purpose of the present investigation was to examine the association between physiological reactivity to peer stressors and physical and relational aggression. Potential moderation by actual experiences of peer maltreatment (i.e., physical and relational victimization) and gender were also explored. One hundred ninety-six children (M = 10.11 years, SD = 0.64) participated in a laboratory stress protocol during which their systolic blood pressure, diastolic blood pressure, and skin conductance reactivity to recounting a relational stressor (e.g., threats to relationships) and an instrumental stressor (e.g., threats to physical well-being, dominance, or property) were assessed. Teachers provided reports of aggression and victimization. In both boys and girls, physical aggression was associated with blunted physiological reactivity to relational stress and heightened physiological reactivity to instrumental stress, particularly among youth higher in victimization. In girls, relational aggression was most robustly associated with blunted physiological reactivity to relational stressors, particularly among girls exhibiting higher levels of relational victimization. In boys, relational aggression was associated with heightened physiological reactivity to both types of stressors at higher levels of peer victimization and blunted physiological reactivity to both types of stressors at lower levels of victimization. Results underscore the shared and distinct emotional processes underlying physical and relational aggression in boys and girls.

Borderline personality features as a predictor of forms and functions of aggression during middle childhood: Examining the roles of gender and physiological reactivity

The present longitudinal investigation examined borderline personality features as a predictor of aggression 1 year later. Moderation by physiological reactivity and gender was also explored. One hundred ninety-six children (M = 10.11 years, SD = 0.64) participated in a laboratory stress protocol in which their systolic blood pressure, diastolic blood pressure, and skin conductance reactivity to recounting a relational stressor (e.g., threats to relationships or exclusion) were assessed. Teachers provided reports on subtypes of aggressive behavior (i.e., reactive relational, proactive relational, reactive physical, and proactive physical), and children completed a self-report measure of borderline personality features. Path analyses indicated that borderline personality features predicted increases in reactive relational aggression and proactive relational aggression among girls who evinced heightened physiological reactivity to interpersonal stress. In contrast, borderline personality features predicted decreases in proactive physical aggression in girls. Findings suggest that borderline personality features promote engagement in relationally aggressive behaviors among girls, particularly in the context of emotional dysregulation.

Baseline autonomic nervous system arousal and physical and relational aggression in preschool: the moderating role of effortful control

The current study investigates whether established associations between physical aggression and low autonomic nervous system arousal, as indexed by heart rate and blood pressure, also apply to the study of the development of relational aggression. Baseline heart rate and blood pressure were collected in two samples of preschoolers, and teachers reported on classroom physical and relational aggression. In Study 1, lower systolic and diastolic blood pressure were related to increased engagement in relational aggression among older preschoolers. In Study 2, lower heart rate and blood pressure predicted increased engagement in classroom physical and relational aggression concurrently and across a preschool year in some cases. Low baseline arousal-aggression associations were strongest for children with poorer self-regulation abilities, whereas high self-regulation appeared to protect children with low heart rate and blood pressure from engagement in aggressive classroom behavior. These findings suggest the utility of examining baseline physiological measures in the study of relational aggression as well as physical aggression. Implications for interventions targeted to physical and relational aggression in early childhood are discussed.

Methylphenidate and comorbid anxiety disorder in children with both chronic multiple tic disorder and ADHD

OBJECTIVE

To determine if comorbid anxiety disorder is associated with differential response to immediate release methylphenidate (MPH-IR) in children with both ADHD and chronic multiple tic disorder (CMTD).

METHOD

Children with (n = 17) and without (n = 37) diagnosed anxiety disorder (ANX) were evaluated in an 8-week, placebo-controlled trial with rating scales and laboratory measures.

RESULTS

The +ANX group obtained more severe parent, teacher, and child ratings of anxiety and more severe parent ratings of depression, tics, oppositional defiant disorder (ODD), and peer aggression than the -ANX group. Treatment with short-term MPH-IR was associated with improvement in ADHD, ODD, and peer aggression in the +ANX group. When controlling for ODD severity, there were no apparent group differences in therapeutic response to MPH-IR in children ±ANX. There was little evidence that MPH-IR contributed to improvement in anxiety or depression symptoms in the +ANX group. There was some indication that children with comorbid anxiety may differentially experience greater increase in systolic blood pressure (0.5 mg/kg of MPH-IR > placebo).

CONCLUSION

Findings suggest that the co-occurrence of diagnosed CMTD+ADHD+ANX represents a particularly troublesome clinical phenotype, at least in the home setting. Comorbid anxiety disorder was not associated with a less favorable response to MPH-IR in children with ADHD+CMTD, but replication with larger samples is warranted before firm conclusions can be drawn about potential group differences.

Selective breeding for infant rat separation-induced ultrasonic vocalizations: developmental precursors of passive and active coping styles

Human depression and anxiety disorders show inherited biases across generations, as do antisocial disorders characterized by aggression. Each condition is preceded in children by behavioral inhibition or aggressive behavior, respectively, and both are characterized by separation anxiety disorders. In affected families, adults and children exhibit different forms of altered autonomic nervous system regulation and hypothalamic-pituitary-adrenal activity in response to stress. Because it is difficult to determine mechanisms accounting for these associations, animal studies are useful for studying the fundamental relationships between biological and behavioral traits. Pharmacologic and behavioral studies suggest that infant rat ultrasonic vocalizations (USV) are a measure of an early anxiety-like state related to separation anxiety. However, it was not known whether or not early ultrasound emissions in infant rats are markers for genetic risk for anxiety states later in life. To address these questions, we selectively bred two lines of rats based on high and low rates of USV to isolation at postnatal (P) 10 days of age. To our knowledge, ours is the only laboratory that has ever selectively bred on the basis of an infantile trait related to anxiety. The High and Low USV lines show two distinct sets of patterns of behavior, physiology and neurochemistry from infancy through adulthood. As adults High line rats demonstrate "anxious"/"depressed" phenotypes in behavior and autonomic nervous system (ANS) regulation to standard laboratory tests. In Lows, on the other hand, behavior and autonomic regulation are consistent with an "aggressive" phenotype. The High and Low USV lines are the first genetic animal models implicating long-term associations of contrasting "coping styles" with early attachment responses. They thus present a potentially powerful model for examining gene-environment interactions in the development of life-long affective regulation.

Psychobiology of persistent antisocial behavior: Stress, early vulnerabilities and the attenuation hypothesis

Stress experienced during the sensitive prenatal, postnatal and early childhood periods of brain development can have damaging consequences for developing biological systems. Stressors imposed by early physical vulnerabilities and an adverse care giving environment is proposed to set in motion early precursors of later persistent antisocial behavior. The purpose of this report is to present an integrated theoretical perspective of potential mechanisms involved in the development of persistent antisocial behavior with an emphasis on early stressors and the neuroendocrinology of stress. The attenuation of endocrine physiology of the stress system is considered a key mechanism involved in persistent antisocial behavior. The amygdala is considered a structure/process linking subjective experiences, emotional learning, brain development and stress physiology. Attenuated cortisol level subsequent to early vulnerabilities is considered a risk marker for persistent antisocial behavior.