There is considerable converging evidence that serotonin-system dysfunction is correlated with suicidal behaviours. Serotonin neurones have their cell bodies in the dorsal raphe nucleus, while their axons innervate most of the brain including the ventral prefrontal cortex. Postmortem study of the concentration of serotonin and its major metabolite, 5-hydroxyindoleacetic acid (5-HIAA), in brain tissue has limitations such as the postmortem loss of these substances. Because most of this decline takes place in the first 2 h postmortem, results from different studies are comparable. Of seven studies that examined the postmortem brainstem, five found modest but significant reductions of serotonin or 5-HIAA in suicide victims compared to controls, while two studies found no changes. (2) Studies of other brain regions including the prefrontal cortex have generated results that are more equivocal. The reductions in serotonin or 5-HIAA are independent of psychiatric diagnosis, and, despite early reports to the contrary, are independent of suicide method. Thus these reductions appear to be related specifically to the suicidal status of the subjects studied.(3)
Was this article helpful?