This is a response to Cliff Anderson's rebuttal¹ to my NMDA antagonist neurotoxicity paper I published online years ago², and a retraction of my original claims. As this is intended as informal commentary, the style is somewhat free form.

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I feel I should explain where I went wrong. Although I do not believe this explanation excuses the mistakes I made, you do speculate about my motivations, so I think it fair to respond to that. When I published the NAN argument -- which you rightly critique -- I did not, as you suggest, believe I suffered cognitive impairment or lasting psychosis from DXM use. I do appreciate that you dismissed the possibility of fraud; it has always been important to me to provide accurate and balanced information. I failed to do so, in this case, and am quite ashamed of that.

Four unrelated events occurred in the six months prior to publishing the NAN warning. First, I received an influx of reports of lasting cognitive impairment from DXM users (in retrospect, of course, I realize they were not sufficient for the conclusions I drew). Second, I was contacted by several very vocal critics of the DXM FAQ, two of whom were angry enough to make threats. Third, I discovered that adolescents were making extensive use of DXM and misunderstanding, if not dismissing outright, some of the more measured warnings in the FAQ. In response I made the classic drug war blunder: if they aren't listening, try scaring them. Fourth, and perhaps most influential, I was experiencing a hypomanic episode and did not recognize either it or the mistakes I was making (I do not know whether DXM triggered the episode itself, though when I was diagnosed as bipolar, I had long ceased DXM use and history prior to DXM use was considered relevant).

Even at the time I expected a critique or rebuttal from the community; the only one I recall receiving was to the claim that nitrous oxide was an NMDA antagonist. I found this quite surprising. I should have submitted the paper to others for review prior to publication online, just as I did with the FAQ itself.

1. In reference to the sudden increase from the three reports of impairment from DXM to "dozens": Some were from people (largely ketamine and PCP users) answering questions about dissociative use and cognitive impairment. The rest were solicited responses to the FAQ feedback form. As such they are useless as evidence, being both insufficient in number and obviously biased.
   
   
2. In reference to anticholinergics: that was pure sloppiness in note-taking. I reread the original papers I kept on the subject and made a mistake.
   
   
3. In reference to education: I wish I could plead ignorance in this case, but I have had sufficient formal education in logic, statistics, and research to know better.
   
   
4. In reference to the tone of the paper: The original publication was on Usenet, and I attempted simultaneously to act as an authority on a subject, and an average Usenet poster in a common, if indefensible, style of that time (i.e., make ridiculously aggressive claims and wait for rebuttal). Yet another mistake I do not intend to repeat.
   
   

I do not have sufficient evidence to state any conclusion on the subject beyond what's obviously available in published literature (i.e., NAN occurs in lab rats). Clearly some dissociative users show lasting impairment, and that's worth noting, but concluding NAN is involved is premature. If long-term impairments following dissociative use seems consistent with the speculated functions of the brain regions affected by NAN, there's no sound reason to believe it's anything beyond coincidence.

Certainly, the more I've learned on the subject, the more painfully aware I've become of how limited our knowledge is. Until I have sufficient means to resume my formal education -- and assuming I have not burned too many bridges to do so -- my own knowledge will be second-hand at best, coming from published material and communication with those doing the actual research.

Having reviewed the risks of dissociative use, what is known of those risks, and the reports -- worthless for drawing conclusions, yet still interesting -- from people claiming to suffer long-term impairment from dissociatives, I would not use dissociatives at high doses for extended periods of time, and I think people would do best to avoid frequent or heavy use of dissociatives entirely. Whether due to NAN or not, I find it plausible that impairment due to dissociative use may reappear, or only become apparent, many years after use, i.e., after gradual age-related neuron loss.