Platelet 5-HT2A receptor binding and tryptophan availability in depression are not associated with recent history of suicide attempts but with personality traits characteristic for suicidal behavior.

BACKGROUND: Abnormalities in the serotonergic (5-HT) system have been implicated in the pathogenesis of suicidal behavior. Studies on peripheral serotonergic parameters as a measure for central serotonergic function in suicidal patients appear to be promising, yet failed to show a clear association with suicidality. The objective of this study was to elucidate the role of serotonergic blood parameters in depressed suicidal patients and to examine their usefulness as a potential biological marker for suicidality. A number of personality traits were assessed in order to provide a basis for a psychobiological model of suicidal behavior. METHODS: Depressed patients with a recent suicide attempt (SA; n = 59) were compared to those without history of suicide attempts (NSA; n = 28). 5-HT2A receptor binding in platelets and tryptophan/amino acid ratio in plasma were measured. Acute psychopathology and personality traits as well as characteristics of suicide attempts were assessed. RESULTS: There was no significant difference between SA and NSA in terms of peripheral serotonergic parameters as well as personality traits. However, the whole sample showed associations between certain personality traits and serotonergic platelet parameters. Furthermore, we observed a relation between suicidal ideation, lethality of suicide attempts and peripheral serotonergic markers. LIMITATIONS: The number of cases with data on peripheral markers is relatively low. The potential influence of antidepressant medication previous to study inclusion has to be taken into account. The study focussed on depressed patients only. CONCLUSIONS: Low serotonergic function is involved in the pathogenesis of suicidality, whereas the use of platelet 5-HT2A receptor activity and tryptophan availability as biological markers for suicidality in depressed patients could not be proven an appropriate tool. Alterations in the serotonergic system are associated with trait aggression and other character dimensions.

A multicenter study about Neurobiology of Suicidal Behavior: design, development, and preliminary results.

The subproject 1.5 "Neurobiology of Suicidal Behavior" is a multicenter study assessing peripheral parameters of the serotonergic, noradrenergic, and dopaminergic transmitter systems. Additionally, stress hormones and the lipid system as well as inhibitory and excitatory amino acids will be investigated. The different parameters are collected in cerebral spinal fluid (CSF), blood, and saliva. Patients with a depressive spectrum disorder with and without a suicide attempt (during the last three weeks) and being medication free for two weeks are included in the study. So far, 103 patients and controls have been recruited. The design and development of this project as well as interconnections with the others subprojects are described. Preliminary results about the stress hormone system and suicidality are presented.

Suicide prevention by lithium SUPLI--challenges of a multi-center prospective study.

Several studies have shown that there is a significantly increased risk of suicide related mortality in patients with a positive history of suicide attempts. The SUPLI-Study is the first prospective, randomized, double blind, placebo controlled multi-center trial focusing on the proposed suicide preventive effects of lithium in patients with suicidal behavior but not suffering from bipolar disorder or recurrent major depressive disorder. Patients with a recent history of a suicide attempt are treated with lithium versus placebo during a 12 month period. The hypothesis is that lithium treatment will lead to a 50% reduction of suicidal behavior. The protocol of the study and preliminary results are presented.