Skin Conductance Habituation and Cerebrospinal Fluid 5-Hydroxyindoleacetic Acid in Suicidal Patients

The concentration of 5-hydroxyindoleacetic acid (5-HIAA) in the CSF and psychophysiologic variables, such as habituation of the skin conductance response, were measured in 35 drug-free suicidal inpatients. The suicide attempters were classified into nonviolent & violent. All violent attempters were fast habituators, as were all 4 patients who in a one-year follow-up were found to have completed suicide. There was no correlation between CSF 5-HIAA and habituation rate.