Citation

Provençal N, Suderman MJ, Vitaro F, Szyf M, Tremblay RE. PLoS One 2013; 8(7): e69481.

Affiliation

Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada ; Research Unit on Children's Psycho-Social Maladjustment and Ste-Justine Hospital Research Center, University of Montreal, Montreal, Canada ; Sackler Program for Epigenetics and Psychobiology, McGill University, Montreal, Quebec, Canada.

Copyright

(Copyright © 2013, Public Library of Science)

DOI

10.1371/journal.pone.0069481

PMID

23922720

Abstract

BACKGROUND: An increasing number of animal and human studies are indicating that inflammation is associated with behavioral disorders including aggression. This study investigates the association between chronic physical aggression during childhood and plasma cytokine levels in early adulthood. METHODOLOGY/PRINCIPAL FINDINGS: Two longitudinal studies were used to select males on a chronic physical aggression trajectory from childhood to adolescence (n = 7) and a control group from the same background (n = 25). Physical aggression was assessed yearly by teachers from childhood to adolescence and plasma levels of 10 inflammatory cytokines were assessed at age 26 and 28 years. Compared to the control group, males on a chronic physical aggression trajectory from childhood to adolescence had consistently lower plasma levels of five cytokines: lower pro-inflammatory interleukins IL-1α (T(28.7) = 3.48, P = 0.002) and IL-6 (T(26.9) = 3.76, P = 0.001), lower anti-inflammatory interleukin IL-4 (T(27.1) = 4.91, P = 0.00004) and IL-10 (T(29.8) = 2.84, P = 0.008) and lower chemokine IL-8 (T(26) = 3.69, P = 0.001). The plasma levels of four cytokines accurately predicted aggressive and control group membership for all subjects. CONCLUSIONS/SIGNIFICANCE: Physical aggression of boys during childhood is a strong predictor of reduced plasma levels of cytokines in early adulthood. The causal and physiological relations underlying this association should be further investigated since animal data suggest that some cytokines such as IL-6 and IL-1β play a causal role in aggression.

Language: en