The Nobel Prize in Medicine was awarded today to two Australians, Barry J. Marshall and J. Robin Warren for establishing that a bacterium, Helicobacter pylori, is the cause of peptic ulcers. See, for example, _the Chronicle of Higher Education_ (http://chronicle.com/free/2005/10/2005100301n.htm) and BBC news ( http://news.bbc.co.uk/1/hi/health/4304290.stm).
When I first heard of their work I was delighted, because stomach ulcers have long been considered one of the best examples of a psychosomatic disorder. To learn that ulcers were shown to be caused by an infectious agent and not by a punishing superego was one more example (and a striking one) of the unscientific irrelevance of psychoanalytic theorizing. And yet. Not that there's anything to be said in support of the silly psychoanalytic version, but there is an extensive literature which links ulcers in experimental animals and stress. [What follows is off the top of my head, sans references (got 'em somewhere), but I think it's reasonably accurate]. When I went to grad school, one of the most celebrated of animal experiments was Brady's (1958) so-called "executive monkey" study. Monkeys were studied in pairs (the "yoked-control" method). Both monkeys of each pair received the same punishing electric shock. One monkey could turn them off; the other could not. Guess which one got the ulcers? Hence the analogy to the executive, whose alleged ulcer- proneness was claimed to be due to the stressful nature of the decisions he (it mostly was, back then) had to make. The study was considered brilliant, and often praised as one of the finest achievements of the scientific method. Unfortunately, there was also a rat literature, and it seemed to show the exact opposite, namely that it was the rat exposed to _uncontrollable_ shock who was more ulcer-prone. A vast and confusing literature followed. Certainly, I was. As I recall, it turned out that the executive monkey effect could not be replicated. The best reason I heard of to explain why Brady got the results he did was that, far from the study being a model experiment, he committed a serious blunder in randomization. This was to assign the monkeys which couldn't learn to turn shock off to the control group. They just happened to be less prone to ulcers. But does the Nobel Prize-winning work on Helicobacter pylori as the cause of ulcers obviate the stress hypothesis? Probably not. For one thing H. pylori infection is extremely common. According to the _Chronicle_ piece, "The bacterium lives in the stomach of about half of all people worldwide but most people experience no symptoms". So if we can live happy, ulcer-free lives despite infection, clearly there's more involved that just becoming infected. Given the extensive animal literature (the non-discredited part, I mean) showing that stress in the form of uncontrollable shock causes (or at least contributes) to ulcers, I think the stress hypothesis remains viable. I've got at least one review paper somewhere which argues exactly that. Unfortunately, few (and apparently, not the Nobel Committee) are saying anything about that. Instead, it's H. pylori all the way down. [irrelevant note: I think I've got the HTLM problem under control. See if I have.] Stephen --------------------------------------------------------------------- Stephen L. Black, Ph.D. tel: (819) 822-9600 ext 2470 Department of Psychology fax:(819) 822-9661 Bishop's University e-mail: [EMAIL PROTECTED] Lennoxville, QC J1M 1Z7 Canada Dept web page at http://www.ubishops.ca/ccc/div/soc/psy TIPS discussion list for psychology teachers at http://faculty.frostburg.edu/psyc/southerly/tips/index.htm ---------------------------------------------------------------------- --- You are currently subscribed to tips as: archive@jab.org To unsubscribe send a blank email to [EMAIL PROTECTED]
