<prompt> 5-HIAA Hydroxyindoleacetic Acid is a metabilite of which of the following neurotransmitters?NoradrenalineSerotoninGABAGlutamine  <response>: Serotonin 5-HT is metabilised the key enzyme Mono Amino Oxidase MAO and one of the main metabolite of clinical significance is 5-HIAA. The CSF levels of 5-HIAA Hydroxyindoleacetic Acid is low in patients who committed suicide, in depression and violence. It is considered to be associated with poor impulse control. It can be used to predict violent suicide. It is not known to be reduced in OCD. Ref: Kaplan Sadocks Synopsis of Psychiatry, By Benjamin J Sadock, M.D., Harold I. Kaplan, Virginia A Sadock, M.D, 10th Edition, Page : 265 