Impulsive aggression and central serotonergic system function in humans: an example of a dimensional brain-behavior relationship.

A dimensional relationship between central serotonergic (5-HT) system function and indices of suicidal and impulsive aggressive behaviors has been suggested by more than a decade of research in patients with psychiatric disorders. This paper reviews a series of studies conducted in healthy male individuals and in male patients with major mood and/or personality disorder involving pharmacochallenge and neurochemical strategies designed to explore the role of central 5-HT system function in the regulation of suicidal and impulsive aggressive behavior in humans. The results of these studies suggest that reduced overall central 5-HT function in the limbic-hypothalamic system is associated with suicidal and/or impulsive aggressive behaviors in patients with major mood and/or personality disorders and that diminished 5-HT post-synaptic receptor function in this brain region may be an important biological correlate of these behaviors.