Citation

Booij L, Tremblay RE, Leyton M, Seguin JR, Vitaro F, Gravel P, Perreau-Linck E, Lévesque ML, Durand F, Diksic M, Turecki G, Benkelfat C. PLoS One 2010; 5(6): e11255.

Affiliation

Department of Psychiatry, McGill University, Montreal, Canada.

Copyright

(Copyright © 2010, Public Library of Science)

DOI

10.1371/journal.pone.0011255

PMID

20582306

PMCID

PMC2889822

Abstract

BACKGROUND: Adults exhibiting severe impulsive and aggressive behaviors have multiple indices of low serotonin (5-HT) neurotransmission. It remains unclear though whether low 5-HT mediates the behavior or instead reflects a pre-existing vulnerability trait. METHODOLOGY/PRINCIPAL FINDINGS: In the present study, positron emission tomography with the tracer alpha-(11)Cmethyl-L-tryptophan ((11)C-AMT) was used to compare 5-HT synthesis capacity in two groups of adult males from a 21-year longitudinal study (mean age +/- SD: 27.1+/-0.7): individuals with a history of childhood-limited high physical aggression (C-LHPA; N = 8) and individuals with normal (low) patterns of physical aggression (LPA; N = 18). The C-LHPA males had significantly lower trapping of (11)C-AMT bilaterally in the orbitofrontal cortex and self-reported more impulsiveness. Despite this, in adulthood there were no group differences in plasma tryptophan levels, genotyping, aggression, emotional intelligence, working memory, computerized measures of impulsivity, psychosocial functioning/adjustment, and personal and family history of mood and substance abuse disorders. CONCLUSIONS/SIGNIFICANCE: These results force a re-examination of the low 5-HT hypothesis as central in the biology of violence. They suggest that low 5-HT does not mediate current behavior and should be considered a vulnerability factor for impulsive-aggressive behavior that may or may not be expressed depending on other biological factors, experience, and environmental support during development.

Language: en