June 1986

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

Author Affiliations

From the Department of Psychiatry and Psychology, Karolinska Institute, Stockholm (Drs Edman, Asberg, and Levander), and the Department of Psychology, University of Stockholm (Dr Schalling).

Arch Gen Psychiatry. 1986;43(6):586-592. doi:10.1001/archpsyc.1986.01800060080010

• The concentration of 5-hydroxyindoleacetic acid (5-HIAA) in the cerebrospinal fluid (CSF) and psychophysiologic variables, such as habituation of the skin conductance response, were measured in 35 drug-free, suicidal inpatients. Twentyfour patients were hospitalized after a suicide attempt, and another 11 had suicidal ideation. The suicide attempters were classified into nonviolent (drug overdoses taken orally, or a single wrist cut) and violent (all other methods). As in previous studies, the suicide attempters had significantly lower CSF concentrations of 5-HIAA compared with healthy, matched controls. The distribution of habituation rate was bimodal (slow and fast habituators). All violent attempters were fast habituators, as were all four patients who in a one-year follow-up were found to have completed a suicide (all by violent methods). The lowest frequency of fast habituators was found in the group of patients with suicidal ideation. There was no correlation between CSF 5-HIAA and habituation rate. A combination of these two variables yielded a highly significant correlation with type of suicide behavior, both retrospectively and prospectively.