• serotonin;
  • homicide;
  • suicide;
  • forensic psychiatry

Objective: The aim of this study was to investigate the relationship between low cerebrospinal fluid 5-hydroxyindoleacetic acid (CSF 5-HIAA) and aggressive acts in mentally disordered violent offenders.

Method: CSF concentrations of 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid and 4-hydroxy-3-methoxyphenyl glycol weremeasured in 35 drug-free men convicted of homicide and currently undergoing forensic psychiatric investigation in a high security hospital.

Results: The mean metabolite concentrations in the homicide offenders did not differ from those of age- and body-height matched malecontrol subjects. One-third of the murderers had made oneor several suicide attempts, and their mean concentration ofspinal fluid 5-HIAA was significantly lower than that ofthe remaining murderers. Subjects with impulse controldisorder also had lower mean CSF 5-HIAA. A consistentpattern of higher CSF 5-HIAA in subjects with moreself-reported anxiety traits was observed.

Conclusion: The association between serotonin and suicidal behaviour holds for yet another subject group. Determining CSF 5-HIAA might be worth while in the routine assessment of psychiatrically ill homicide offenders.