Saturday, October 16, 2010

Beyond Pagoclone, Part 3

In this post we look at a couple of alternative over-the-counter supplements that have been tried as fluency enhancers. In the previous posts, all of the alternative drugs discussed require a doctor's prescription except for Phenibut.

Some stutterers have reported mildly improved fluency when taking an over-the-counter supplement 5-HTP (see blog). Since 5-HTP is claimed to be a serotonin activity enhancer, the question arises as to how this may come about. The answer may Iie in some research conducted by a group of Stanford University medical researchers (see Andrews et al, Journal of Neurochemistry, 1978, vol. 30, pp. 465-470; also see They claim that 5-HTP may be a dopamine depletor based on their studies with rats. Thus, reducing the levels of dopamine according to the dopamine hypothesis of stuttering should improve fluency. Whether or not 5-HTP has long lasting effects or has only a transient impact is an open question. To my knowledge, no controlled double blind trials have been conducted to determine 5-HTP's effect on fluency.

Vitamin B-6 has also been tried as a fluency enhancer (see blog cited above). The idea here is that vitamin B-6 is involved in the production of GABA, which inhibits the action of dopamine. But the situation is a bit more complicated than that as we see in the somewhat simplified diagram below.

Indeed, B-6, along with Glutamate and GAD (glutamic acid decarboxylase), is involved in the GABA synthesis process (denoted by the green directed lines). And GABA inhibits the action of dopamine as shown by the red directed line.  But note also that B-6 reacts with GABA along with GABA-T (GABA-transaminase) to produce succinic acid which is involved in the negative feedback inhibition of GAD (again denoted by the red directed line). In addition, we also see from the Figure that B-6, along with Dopa is involved in the production of dopamine. So B-6 has a positive effect on the production of GABA, but also a negative effect on GABA levels because of its reaction with GABA and GABA-T (producing succinic acid), and an additional negative effect by way of being involved in the synthesis of dopamine. Obviously vitamin B-6 plays a delicate balancing act in maintaining an equilibrium among different neurotransmitters except perhaps in the brains of stutterers. Based on the above discussion, it is very difficult to determine what the net effect of taking vitamin B-6 might be on the fluency of any particular individual.

1 comment:

Anonymous said...

Hi. Your blog seems interesting and useful. However, I'm puzzled that it seems entirely anonymous - unless I'm missing something. Personally, I'm always skeptical and suspicious of anything that's written anonymously. I think, who is this guy? What's his agenda, and what's he trying to hide?

Why not tell your readers who you are and why you're writing, like a normal blog? I think you'd be better respected and more widely read, and your ideas would be more likely to be accepted.