GH response to intravenous clonidine challenge: absence of relationship with behavioral irritability, aggression, or impulsivity in human subjects

Moderating effects of childhood maltreatment on associations between social information processing and adult aggression

BACKGROUND

Associations between early life maltreatment, social information processing (SIP) and aggression in childhood and adolescence have been widely documented. Few studies have examined the importance of childhood maltreatment independent of SIP in the etiology of adult aggression. Furthermore, moderating effects of childhood maltreatment on the SIP-aggression links have not been explored.

METHOD

Hierarchical, multi-level models were fitted to data from n=2752 twins aged 20-55 years from the PennTwins Cohort. Adult aggression was assessed with the Life History of Aggression questionnaire. Childhood maltreatment was measured using the Childhood Trauma Questionnaire. Two aspects of SIP were examined: hostile attribution biases (HAB); negative emotional responses (NER).

RESULTS

Childhood maltreatment was positively correlated with adult aggression, independently of HAB and NER. In addition, childhood maltreatment moderated the relationships between both aspects of SIP and adult aggression. Specifically, the relationship between NER and aggression was stronger among individuals with higher levels of childhood maltreatment and NER was not associated with aggression for adults who experienced low levels of childhood maltreatment. Moderating effects of childhood maltreatment on the NER-aggression link were supported for total childhood maltreatment, emotional neglect and emotional abuse. In contrast, HAB was more strongly associated with adult aggression at lower levels of emotional abuse and physical neglect.

CONCLUSIONS

The current study provides insight into the mechanisms by which early life experiences influence adult aggression. Our findings suggest that childhood maltreatment may not only lead to increased levels of aggression in adulthood but may also modify the associations between SIP and adult aggression.

The neurochemistry of human aggression

Various data from scientific research studies conducted over the past three decades suggest that central neurotransmitters play a key role in the modulation of aggression in all mammalian species, including humans. Specific neurotransmitter systems involved in mammalian aggression include serotonin, dopamine, norepinephrine, GABA, and neuropeptides such as vasopressin and oxytocin. Neurotransmitters not only help to execute basic behavioral components but also serve to modulate these preexisting behavioral states by amplifying or reducing their effects. This chapter reviews the currently available data to present a contemporary view of how central neurotransmitters influence the vulnerability for aggressive behavior and/or initiation of aggressive behavior in social situations. Data reviewed in this chapter include emoiric information from neurochemical, pharmaco-challenge, molecular genetic and neuroimaging studies.