Thank you for the opportunity to respond to Drs. Ebrahim and Fenwick’s letter.
We are somewhat confused by the content of their letter. We note that in 2000+ words they failed to address, raise, contradict or even comment on even a single point regarding the main conclusions of our review article (Pressman et al., 2007b).
Specifically, they do not comment on or criticize our conclusions that:
- 1There is no scientific evidence that alcohol predisposes, primes or precipitates sleepwalking.
- 2There is extremely limited evidence that alcohol in social drinkers increases slow wave sleep (SWS).
- 3There is no evidence that SWS is increased in alcohol abusers of any description or diagnosis.
- 4The Alcohol (Challenge) Provocation Test is a completely unvalidated test.
- 5In the severely alcohol intoxicated individual there is no scientific reason to attribute violence or sexual abuse to sleepwalking.
Instead, Drs. Ebrahim and Fenwick spend almost all their time discussing tangential matters that do not bear on our main conclusions and in some cases don’t appear related to this article at all. Most of the content appears very similar to another letter to editor they sent to Sleep Medicine Reviews (SMR) regarding a completely different article and editorial published in that journal (Ebrahim and Fenwick, 2007; Pressman 2007a; Mahowald et al., 2007). Readers may also want to look at our response to that letter (Pressman et al., 2007a).
Among the various tangential topics addressed by Drs. Ebrahim and Fenwick, we were most mystified by their claim we were unacceptably ‘biased’ towards the role of increased SWS in the occurrence of sleepwalking compared to some other unspecified theory. They state that they apparently arrived at this peculiar conclusion because we did not cite what appears to be a random assortment of journal articles that they list in their letter. We strongly suggest that Drs Ebrahim and Fenwick read the articles they cited if they have not done so already, as we find nothing in them to support an alternate theory of sleepwalking. Ebrahim and Fenwick apparently are referring to a completely different article published in a completely different journal. They appear to be paraphrasing – out-of-context – two letters to the editor of SMR by Dr. Rosalind Cartwright concerning another previously published article by one of us (MRP) (Pressman, 2007a; Cartwright 2007a,b). Their comments suggest they are unfamiliar with the extensive research that supports the role of increased SWS in sleepwalking. The role of increased SWS in sleepwalking is very well established and supported by numerous published empirical studies in the sleep laboratory that address this question directly and have highly significant statistical results (Pressman, 2007a; Zadra et al., 2008; Joncas et al., 2002; Pilon et al., 2006). On the other hand, there is no generally accepted alternate theory of sleepwalking. However, interested readers might want to look at the exchange of letters to editor between Dr. Cartwright and Dr. Pressman in SMR (Cartwright 2007a,b; Pressman, 2007b, 2008) for further information. Thus, yes, we freely admit that we are biased towards theories that are supported by extensive empirical scientific research and biased against theories that have little or no empirical support.
Drs. Ebrahim and Fenwick also continue to defend their use of the Alcohol Challenge or Alcohol Provocation Test. We feel obligated to state for at least the fifth time in print that this test should not be permitted for clinical or forensic purposes (Pressman, 2007a; Pressman et al., 2007b,c,d). It is a completely unvalidated test with no published data regarding its sensitivity, specificity or reliability. It has never been replicated independently. No normative data for this test regarding any patient group including sleepwalkers exists. We again call upon Dr. Ebrahim to stop using this test until such time as the published scientific data supports its use.
In summary, nothing in Drs. Ebrahim and Fenwick’s letter addresses or contradicts the main points of our article. There is no scientific evidence that alcohol is involved in the occurrence of sleepwalking in any way.