Increased suicidal tendency is associated with:

Decreased levels of 5 HIAA (which is a metabolite of serotonin) are related to increased risk of suicide. (|) 5-HIAA (5-hydroxyindoleacetic acid) (|) MHPG (3-methoxy-4-hydroxyphenylglycol) Increased risk of suicide. (|) HVA (homovanillic acid) Schizophrenia and other conditions involvingpsychosis (|) HVA Parkinson's diseaseTreatment with antipsychotic agentsDepression Two alleles, U and L are involved in the gene polymorphism for the enzyme tryptophan hydroxylase involved in serotonin synthesis. Of the two alleles,presence of L allele increases suicidal riskmore than U allele. For example, multiple suicide attempts was found most often in subjects with the LL genotype and to a lesser extent among those with the UL genotype.