Suicide attempts and impulse control disorder are related to low cerebrospinal fluid 5-HIAA in mentally disordered violent offenders

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. CSF concentrations of 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid and 4-hydroxy-3-methoxyphenyl glycol were measured in 35 drug-free men convicted of homicide and currently undergoing forensic psychiatric investigation in a high security hospital. The mean metabolite concentrations in the homicide offenders did not differ from those of age- and body-height matched male control subjects. One-third of the murderers had made one or several suicide attempts, and their mean concentration of spinal fluid 5-HIAA was significantly lower than that of the remaining murderers. Subjects with impulse control disorder also had lower mean CSF 5-HIAA. A consistent pattern of higher CSF 5-HIAA in subjects with more self-reported anxiety traits was observed. 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.