Spinal Fluid Chemical Levels Linked To Suicidal Behavior 85
An anonymous reader writes "For the first time, researchers have found that a chemical in the brain called glutamate is linked to suicidal behavior. While previous research and drugs have targeted serotonin to fight severe depression, this study shows that more attention should be paid to this chemical."
Re:Suggestion: Stop linking to Medical Daily. (Score:4, Informative)
TFA contains a direct link to the original article in the journal Neuropsychopharmacology [nature.com] FFS, can we advance to the next stage of logical fallacies now ..
Glutamate (Score:5, Informative)
Re:Suggestion: Stop linking to Medical Daily. (Score:5, Informative)
OK then, it's Bush's fault....
The original FA (in the journal) has a reasonable abstract:
The NMDA-receptor antagonist ketamine has proven efficient in reducing symptoms of suicidality, although the mechanisms explaining this effect have not been detailed in psychiatric patients. Recent evidence points towards a low-grade inflammation in brains of suicide victims. Inflammation leads to production of quinolinic acid (QUIN) and kynurenic acid (KYNA), an agonist and antagonist of the glutamatergic N-methyl-D-aspartate (NMDA) receptor, respectively. We here measured QUIN and KYNA in the cerebrospinal fluid (CSF) of 64 medication-free suicide attempters and 36 controls, using gas chromatography mass spectrometry and high-performance liquid chromatography. We assessed the patients clinically using the Suicide Intent Scale and the Montgomery-Åsberg Depression Rating Scale (MADRS). We found that QUIN, but not KYNA, was significantly elevated in the CSF of suicide attempters (p less than 0.001). As predicted, the increase in QUIN was associated with higher levels of CSF interleukin-6. Moreover, QUIN levels correlated with the total scores on Suicide Intent Scale. There was a significant decrease of QUIN in patients who came for follow-up lumbar punctures within 6 months after the suicide attempt. In summary, we here present clinical evidence of increased QUIN in the CSF of suicide attempters. An increased QUIN/KYNA quotient speaks in favor of an overall NMDA-receptor stimulation. The correlation between QUIN and the Suicide Intent Scale indicates that changes in glutamatergic neurotransmission could be specifically linked to suicidality. Our findings have important implications for the detection and specific treatment of suicidal patients, and might explain the observed remedial effects of ketamine.
TL;DR - Suicidally depressed patients seem to have a low level inflammatory process going on. They measure two compounds (out of many) in spinal fluid samples of depressed and control patients that are part of the inflammatory pathway are related to the turnover of glutamate, an amino acid felt to be a neurotransmitter (first link the TFS, a nice short explanation). The glutamate agonist levels were higher in suicidal patients, the glutamate antagonist not.
Potentially a method of quantitating level of suicideality which is a very problematic issue (witness the recent shootings in Connecticut). Very early data. Manuscript submitted but not accepted. At the level of interesting but don't run down to the local Szechuan restaurant and OD on MSG. Oh, and leave the ketamine to the vets.
Glutamate has become very common in modern food (Score:4, Informative)
Glutamate has become very common in all sorts of pre-cooked prepared foods...everything from canned soup to rice-a-roni mixes. It's usually added as something called "MSG" or monosodium glutamate although it is also often added under names such as 'hydrolyzed protein,' 'autolyzed protein,' 'sodium caseinate,' 'autolyzed yeast,' or 'yeast extract.' Food manufacturers have found that adding MSG has a powerful on flavor and makes consumers more likely to 'like' the food and consume greater quantities. A more scientific name for 'glutamate' is 'glutamic acid' and it is a common amino acid found in protein. Food manufacturers have argued successfully for years that since it is an amino acid found in protein, there should be no restrictions on its use. However, as TFA discusses, the quantity of glutamic acid consumed DOES matter and artificially spiking a variety of food with it to make the food taste better may be causing a lot of suicides. Perhaps the school shooter in Connecticut was a heavy consumer of something spiked with MSG such as, for example, many (although not all) varieties of potato chips.
Re:Glutamate has become very common in modern food (Score:2, Informative)
Oh horrors, better start avoiding that unnatural glutamate. All meat, fish, cheese and tomato products are evil and full of that stuff! All that savory tasting stuff.
The reason it tastes good is because it is one of the few things we have taste receptors for. We like added glutamate for the same reason we like all those hearty tasting stews, roasts, casseroles and such that naturally contain it.
That scary sounding monosodium, disodium and such parts in front of the name are mostly irrelevant. They just sound scary but mean that the glutamic acid is added in it's a sodium salt form. (like the scary sounding sodium chloride, table salt)
Simply said:
Glutamic acid is an non-essential amino acid (an amino acid that the body also synthesises by itself) and pretty important for cellural metabolism and liver functions. Perfectly natural thing. The glutamate you eat doesn't magically start screwing up your brain.
Since most mental states (and many problems) are caused by different balances of neurotransmitters it not strange that a change in glutamate balance affects the mind in some way. That is how the brain works. Eating added glutamate does not directly affect the amount of glutamate released in your neurons.