CSF serotonin metabolite (5-HIAA) studies in depression, impulsivity, and violence

A neuroanatomical central nervous system (CNS) mechanism for the expression of emotions and behaviors in animals has now been proposed for over 50 years. More specifically, alterations in CNS serotonin associated with aggressive behavior in certain animal models have been among the most frequent, reliable, and replicable findings. Because alterations in CNS monoamines, i.e., catechols and indols, have been related to hypotheses for affective disorders and associated with both suicidal and aggressive behaviors, human clinical implications have emerged. The original studies, which reported an association between low cerebrospinal fluid 5-hydroxyindole-acetic acid concentration and impulsive, destructive behaviors, particularly where aggression and violence are involved, have now been replicated rather consistently in a number of countries and cultures.