5-HIAA
During the 1980's there was brief interest in a serotonin metabolite called 5-hydroxyindoleacetic acid (5-HIAA). It was found to have low concentrations in the CSF of up to a third of people with depression and very few normal controls.
People with low CSF levels of 5-HIAA have also been found to respond less well to antidepressants and also to be more likely to commit suicide (this is a well replicated finding).
Low levels of 5-HIAA are also associated with increased levels of aggression
People with low CSF levels of 5-HIAA have also been found to respond less well to antidepressants and also to be more likely to commit suicide (this is a well replicated finding).
Low levels of 5-HIAA are also associated with increased levels of aggression
