Serotonergic Parameters of Aggression and Suicide

Aggression as a psychiatric concept requires examination in broad evolutionary terms. It is a complex phenomenon that serves many functions in human and animal life. Neuroanatomical and neurophysiological research have shown that affect and emotion are modulated by the limbic system. Brain loci that are believed to organize specific patterns of aggressive behavior include the lateral hypothalamus, the ventral tegmental area, the centromedial amygdala, the midbrain central grey area, and the central and anterior portions of the septum. Neurotransmitter systems are also thought to play an important role in the expression of aggression. The role of aggression, both inwardly and outwardly directed, in the various major psychiatric disorders has not yet been addressed in any systematic manner. The available evidence appears to indicate that low CSF 5-HIAA, indicative of decreased 5-HT metabolism in the brain, is related in some way to suicidal behavior, irrespective of syndromal or nosological diagnosis.