Sunday, March 26, 2006

Amino acids and depression

     In my reading, I have seen articles that have say taking certain amino acids can help alleiviate depression. The A.A Tyrosine, is a precursor to noerepinephrine, and the essential amino acid phenylanaline is also. I have taken them in the past but gave up in less than a week. The fact that I felt no different, not even side effects like medication, made me quit. Does anyone have any experience woth them. I would like to hear about it before I invest in a whole slew of amino acids. Thanx!


Anonymous Anonymous said...

pathwa from tyrosine to l-dopa is so saturated that taking tyrosine won't do a damn thing anyways...

--      ____   ______  ________ _____     /    \ |      \|   /\   |     \    /      \|   _   \   \/   |  _   \     /___/\   \___|>   >       |__|>   > BORN TO BE WIRED...  /         |       /   /\  |       /  All the sugar and twice the  \_________|______/|___\/__|______/   caffeine of regular netusers!  finger me and make a pgp key come.

6:23 PM  
Anonymous Anonymous said...

The initial tyrosine papers (for depression) were anecdotal.  a controlled trial (double-blind randomized placebo-controlled) over 4 weeks in major depression found no evidence for antidepressant activity of tyrosine.  (Gelenberg AJ et al, J of Affective Disorders, 19: 125-132 (1990)).

Preclinical studies done at MIT at Richard Wurtman's lab have suggested that, in rat, tyrosine administration (as a single amino acid) increases catecholamine synthesis and release, within neurons that have been made to fire frequently, but tyrosine appears to have no effect on neurons that have not been pretreated so as to be highly active in firing frequency.

The increased firing rate may occur acutely during stress, but does not seem to occur during most neural states, including major depression.

The reason tyrosine does not seem to increase catecholamine synthesis and release in non-hyperactive neurons seems to be that adaptive feedback inhibitory mechanisms block this effect.  In other words, there might be a transient increase in norepinephrine and dopamine production, but other mechanisms, such as reduced enzyme activity, reduced neuronal firing rate due to autoreceptor activation, etc. quickly negates the effect, so that the net effect of tyrosine is essentially zero.

Phenylalanine appears to actually decrease catecholamine levels in humans.  The reason is that phenyalanine competes with tyrosine for the large neutral amino acid transporter, which transports tyrosine across the blood-brain barrier.  ie the more phenylalanine in the bloodstream, the less tyrosine that makes it into the brain.  Phenylanine is converted to tyrosine by liver enzymes; these converting enzymes do not appear to occur in brain in appreciable levels.  Thus, the phenylalnine entering the brain is essentially useless or even mildly toxic.

Some animal studies suggested increased catecholamine levels with phenhylalnine administration; however, rats metabolize phenylalanine differently than humans.  Rats transform phenyalanine to tyrosine far more rapidly and efficiently (in liver) than humans, so taking phenylalanine essentially raises tyrosine levels.  This is no different that merely infusing tyrosine in the first place.

In humans, the less efficient liver metabolism of pheneylalnine results in an increased phenylalanine/tyrosine blood ratio, thereby actually decreasing tyrosine entry into brain.

The bottom line: these amino acids are probably at best useless in humans (with the possible exception of tyrosine use for acute stress, of a very intense nature, ie of the sort that officers in military must undergo for prolonged periods of time; even her, this effect is still not well-established).

At worst, these amino acids may have some toxic effects with massive administration; they are also quite expensive.

Hope this helps.

- Dennis Lee (

8:53 PM  
Anonymous Anonymous said...

In article <46a4js$> (Jason Kennerly) writes:

Wurtman's work (MIT lab) suggests that the pathway (tyrosine hydroxylase conversion of tyrosine to L-dopa) is mostly, but not entirely, saturated, so that taking tyrosine does increase (transiently) L-dopa production.   The absence of any apparent behavioral effect appears to be due to other feedback mechanisms, perhaps by reduced neuraonl firing rate, or reduced quantal release.  (ie Actworth IN, During MJ< Wurtman RJ, Brain Research Bulletin, 21: 473-477, 1988).

Thus, it is true anyway that taking tyrosine probably doesn't do anything.

- Dennis Lee

3:08 AM  
Anonymous Anonymous said...

The preferential uptake pathway for amino acids is for protein manufacture, rather than neurotransmitters. For this reason, the serotonin precursor, L-tryptomine, is ineffective for depression, and the same almost certainly holds for amino-acid precursors of other neurotransmitters.

The antidepressant venlafaxine (Effexor) is a selective re-uptake inhibitor of serotonin and norepinephrine and has the same very minor side-effect profile as SSRIs (Prozac, Paxil, Zoloft). Studies suggest that venlafaxine may be more effective for alleviating depression and preventing its reoccurrence in a larger proportion of people than other antidepressants. If you are depressed, work with a physician to find the antidepressant that is most effective for you.

3:23 AM  
Anonymous Anonymous said...

In article <47484e$>,

Actually I was taught that most aromatic amino acids have to share a transporter, so tyr(osine), phe(nylalanine), trp (tryptophan), and the like will all end up competing with each other.

It constantly amazes me how many people take L-phe, expecting to see an increase in catecholamine activity.  Not only will the phe compete with tyr, but it has to be converted in vivo to tyr *anyway*, which is a damned slow process.  Sheesh.  I guess it just goes to show, if you market something, people will buy it.

Tyrosine, on the other hand, really *does* do something for me, but only in certain circumstances.  There's some evidence that the rate-limiting enzyme in dopamine synthesis (tyrosine hydroxylase maybe?) is boosted under certain circumstances, including possibly conditions of DA depletion (due to drugs, lack of sleep, whatever).  I do know that when I've been staying up a *long* time, 2000mg of tyrosine will make it a lot easier to get up the next morning (it won't help me stay up tho).

Sigma-3 receptors also seem to be coupled to DA turnover rates, so I guess one could play around with sigma-3 ligands plus tyrosine hoping to get some sort of increased DA synthesis.

Sheesh!  Like I could *take* that many capsules?!?

Hmm.  Have to try that.  Mechanism?

-- |  Bill White   +1-614-594-3434      | | (check it out!)    | |               If I have a CVA, shoot me up with Special K               |

3:53 AM  
Anonymous Anonymous said... (William E. White ) writes:

I have no idea.

I can only say that I discovered the combo by accident. Later I read that parents in Germany were actually complaining to the government about a drink called "Red Bull" that contained taurine and caffeine, that their kids were staying up all night and such.

Anecdotal as all hell.

From the way it _feels_, it seems almost like the taurine is filling in for some deficiency created by using caffeine. This is of course meaningless as scientific data :)

Taurine is a strange looking 'amino acid'... its not really an amino acid in the conventional sense of the word.

The only thing I can say of it is that cats need a definite amount of it. I bought some when I had a cat, just cause I figured I could feed it to the cat if I didn't want it. The cat now belongs to my fiancee's grandma, and I did use some taurine mixed in with its food, but was suprised to find that taurine actually seemed to do something noticable.

L-phenylalanine probably made me angry because of competition for transporters then, huh? Sad thing is thats all it really did - increase irritability.

--      ____   ______  ________ _____     /    \ |      \|   /\   |     \    /      \|   _   \   \/   |  _   \     /___/\   \___|>   >       |__|>   > BORN TO BE WIRED...  /         |       /   /\  |       /  All the sugar and twice the  \_________|______/|___\/__|______/   caffeine of regular netusers!  finger me and make a pgp key come.

7:39 AM  
Anonymous Anonymous said...

While tryptophan may not be effective in terms of depression itself, it sure helps to be able to get a decent night's sleep.

Same with melatonin.  After several weeks of regular sleep the basic depression may start to be apparent again, but just the relief from the related sleep disorder is *wonderful* and makes life so much more managable!


9:09 AM  

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