Understanding aggression in adolescence by studying the neurobiological stress system: A systematic review.

Aggression in adolescence is an important antecedent of an antisocial developmental pathway. Research on the stress responsivity system, specifically, the hypothalamic-pituitary-adrenal (HPA) axis and autonomic nervous system (ANS), has been instrumental in understanding the development of aggression, yet a recent overview of research on these bio-behavioral associations is currently lacking. We synthesized and analyzed literature since 2011 on HPA-axis (i.e., cortisol) and ANS (i.e., heart rate and skin conductance) measures during rest and stress, with aggression in adolescence (11–19 years). We considered general aggression as well as its subclassifications (e.g., proactive, reactive aggression), and included both self-/other-reports, and laboratory aggression. A literature search (PubMed, Embase, APA PsycINFO) was performed up to March 19, 2021. Sixteen-hundred-fourteen records were screened for eligibility, 28 articles were included in the final synthesis. Although base measures (lower basal cortisol and resting heart rate) related to higher levels of aggression fairly consistently, studies assessing HPAaxis and ANS reactivity yield mixed findings, possibly due to variations in tasks used to evoke reactivity. Furthermore, tentative evidence suggests that lowered arousal relates to proactive forms of aggression, while higher arousal relates to reactive forms of aggression. Finally, the studies show that psychological and social factors, in particular social adversity, internalizing problems, and empathy, impact the association between neurobiological measures and aggression. We recommend that future studies consider different types of aggression using multiple measurement instruments, multiple reactivity tasks, and include a psychosocial assessment. Together, we advocate for a comprehensive biopsychosocial approach to understand what drives aggression in adolescence