big_bad_buff said:
. Suicide it a cowardly thing to do
You have absolutely no clue, do you?
http://www.sciam.com/print_version.cfm?articleID=0006AF90-5BC7-1E1B-8B3B809EC588EEDF
The Neurobiology of Suicidal Behavior
Dr. J. John Mann
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Introduction
The clinical assessment of patients who are at high risk for committing suicide or making a serious suicide attempt has proven to be disappointingly imprecise. Traditional suicide risk factors -- past history of a suicide attempt, male gender, living alone, suffering from a psychiatric disorder, having a formed plan for suicide, making preparations for the suicide attempt, disposing of valued personal possessions, preparing a will -- are often found in cases of suicide. Unfortunately these risk factors are also found in high rates amongst psychiatric patients who never attempt suicide. Thus, we are forced to look elsewhere for features that distinguish the high-risk from the low-risk patient. The observation that there is a genetic risk factor for suicide suggests that there may be biobehavioral traits that predispose patients to commit suicide.
The Biology of Completed Suicide
In the 1960s studies exploring the biological basis of depression found that the brain of patients who died by suicide contained abnormally low levels of the chemical transmitter serotonin and its major breakdown product, the metabolite 5-hydroxyindolacetic acid (5-HIAA). In only half of these suicides was the patient suffering from depression; the others carried diagnoses of schizophrenia, alcoholism, personality disorders, and situational reactions. Prematurely, this area of investigation was abandoned because it was felt to be uninformative about depressive illness. Approximately twenty years later we reviewed this literature and found that the decrease in serotonin and 5-HIAA did not depend on the patient's psychiatric diagnosis or method of death, but instead was related solely to their committing suicide.
Subsequently, a large range of biochemical abnormalities were found to distinguish the brains of suicide victims. The number of imipramine binding sites appears to be decreased in suicide victims -- this may reflect a reduction in the number of serotoninergic nerve terminals. Also, an increase in the number of post-synaptic 5-HT2 serotonin receptors has been demonstrated in their brain, and this receptor has been implicated in a range of brain functions -- emotion, perception, memory, and the release of hormones like prolactin.
Thus there are a number of abnormalities in the serontonergic systems in the brain of suicide victims. These are: 1) consistent with a decrease in serotonin function; 2) independent of psychiatric diagnosis; and 3) probably specific to certain brain regions that determine the likelihood of suicidal behavior.
Although the predominant changes appear to be in the serotonergic system, the noradrenergic system may also be involved -- suicide victims show altered binding of at least two noradrenergic receptor subtypes. Preliminary studies of the cholinergic system have, as yet, identified no abnormalities.
The Biology of Attempted Suicide
Beginning in the 1970s, a succession of studies established that those who had low levels of the serotonin metabolite 5-HIAA in spinal fluid, made a greater number of very serious suicide attempts. This finding has been extended to suicide attempters with personality disorders and those with schizophrenia -- in each of these diagnostic groups suicide attempters have lower levels of 5HIAA than do the non-attempters. One study found that twenty percent of patients admitted to a hospital with a suicide attempt and having low level of CSF 5-HIAA would complete suicide within a year of discharge, compared to only two percent of those with normal levels of CSF 5-HIAA.
Clinical Applications
The level of CSF 5-HIAA has promise as a predictor of future suicidal behavior. It is clinically significant that the CSF 5-HIAA level is not affected by the severity of the depression, but solely discriminates the patients' suicide risk. At the University of Pittsburgh's Clinical Research Center for the Study of Suicidal Behavior a large prospective study is in progress examining CSF 5-HIAA and a range of other biological measures as predictors of suicidal behavior. These studies are important tests of just how usefully these biological indices of risk can assist patient care.
Measurement of 5-HIAA requires a spinal tap, however. A less invasive method for assessing the serotonin system tests blood samples to measure the release of the hormone prolactin into the bloodstream in response to drugs like fenfluramine that cause the release of serotonin in the brain. Two such studies found a blunted prolactin response to fenfluramine in patients who attempted suicide in the past.
The prolactin response to fenfluramine and the CSF levels of 5-HIAA both appear to be subnormal in patients regardless of when the suicide attempt was made, whether it was three years ago or three months ago. This suggests that the serotonin response being measured is an enduring biological trait that might perhaps be genetically transmited, rather than a transient, statedependent measure of suicide risk.
Conclusion
Identifying biological markers of suicidal behavior represents an exciting step forward in suicide research. These markers offer clinicians the hope of one day more precisely predicting who is most at-risk for suicide. The markers could then be used to select patients for preventative treatments that raise their threshold for suicidal behavior and thereby reduce the risk of their carrying out serious suicide attempts. Protecting the patient against suicide in this way buys time for the treatment of the depression and other psychiatric disorders that underlie their suicidal wish
http://www.afsp.org/index-1.htm
The majority (not all) of suicide are committed by people suffering from depression, which is an illness. Noone chooses to be depressed.
I am tired of explaining this to people. I'm suffering now from PTSD myself.
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