Hi, I've updated this old post on dextromethorphan (cough syrrup). I sort of changed the the subject on the BBB post which I didn't mean to do.
In the BBB thread, Steve disscuses his interesting improvements after being on dextromethorphan, DM, for only a few weeks. At first I thought his observations were a placebo effect of the DM. I then recalled a report on DM that I had read and went back to look at it and this report noted that DM can cause dopamine release. It's interesting and should be read by anyone thinking of using DM long term. It was written, I believe, on the concern that DM can be used at high doses to get high. Anyway, there are some interesting points in this long report (para 3.2, 3.3, 3.4). I suspect Steves improvements may be due to the DM creating more dopamine and maybe the DM is also being neuroprotective. This is territory where we should be careful. Try to get all the info you can if you intend to go DM longterm. DM cough syrrup has been around a few decades?, it's currious that Steves improvements have not been noted by the medical profession (or have they?).
If you read the research done by Dr. Hong, Head of Pharmacology at the NIH, he has observed that DM used at very low doses in rodents can be neuroprotective.
Ashley

http://www.ncbi.nlm.nih.gov/entrez/q...&dopt=Abstract

<3.2> What are the side effects and risks of chronic DXM use?

Prolonged, regular use of DXM has some definite risks. The
most common is mania; this has been reported in people who used large
amounts of DXM (especially to self-medicate depression) (1-3). Some
research has linked sigma receptors to schizophrenia (46-49), and
chronic use of NMDA antagonists has been shown to upregulate
(increase) dopamine receptors (50). This could theoretically mean
that DXM could trigger schizophrenia in susceptible individuals,
although nobody knows for sure. DXM could also decrease immune
function due to sigma activity (51). One thing that is known is that
neither DXM nor PCP nor ketamine cause any change in PCP or sigma
receptors.
Another possible effect of long-term DXM use is neurotoxicity.
This has not been observed, but would be consistent with DXM's
hypothesized ability to induce 5HT and dopamine release (52). Such
neurotoxicity would probably be restricted to 5HT (serotonin) neurons,
and be similar to the neurotoxicity resulting from use of MDMA
(ecstasy). Note that no animal studies have ever demonstrated this.
Chronic use of NMDA antagonists seems to modify alcohol
tolerance; this is based mostly on anecdotal evidence and theory, but
it appears to be a very real phenomenon. If true, then it is
important to note that the GABA receptor effects of alcohol may NOT be
changed; in practical terms, you might be a lot drunker than you feel,
and this could possibly lead to alcohol poisoning. Be careful, and
limit yourself to as little alcohol as possible when using DXM. A
recent paper supports the ability of DXM to affect alcohol tolerance
(53).


Reason to believe DM could work at very low doses:
Dr Hong, Head of Pharmacology, NIH

Findings from our research not only reveal an extremely unusual and interesting femtomolar acting compound, but also raise a new concept of using "ultra-low" concentrations of drugs for future therapeutic interventions for inflammation-related diseases. Although whether these in vitro findings can be substantiated in animal studies and eventually tested in clinical trials remain to be studied, the obvious advantages of this low-dose therapy, including the much reduced side effects warrants serious consideration of this approach. To obtain a preliminary glimpse, we have recently observed in an animal study that 100 million-fold lower than the regular dose of DM was effective in reducing the plasma level of alanine aminotransferas (ALT) in LPS/D-galactosamine-induced liver damage (unpublished observations). It is very surprising to learn that DM in such low concentrations is still effective to possess anti-inflammatory effect. However, in view of its potent inhibitory effect on the flavo-containing enzyme (PHOX) we have studied, which is one of the contributors of proinflammatory factors, may explain its potent anti-inflammatory potency and justify further studies of DM or its analogs using different animal models of inflammation.