Your criticism sounds simplistic to me, in that it assumes that all patients in the drug conditions suffer side effects, and no patients in the placebo condition do. In fact, we've know for years that placebos can in fact cause side effects. A Google Scholar search pulls up scores of references on the topic. Here's a blurb pasted from the Wikipedia entry on placebos (which is quite comprehensive and well done):
Another negative consequence is that placebos can cause side-effects associated with real treatment.[104] One example of this is with those that have already taken an opiate, can then show respiratory depression when given it again in the form of a placebo. Martin Bourgeois Professor and Chair Social and Behavioral Sciences Florida Gulf Coast University Fort Myers, FL 33931 ************** Confidentiality Statement ******************** Florida has a very broad public records law. As a result, any written communication created or received by Florida Gulf Coast University employees is subject to disclosure to the public and the media, upon request, unless otherwise exempt. Under Florida law, e-mail addresses are public records. If you do not want your email address released in response to a public records request, do not send electronic mail to this entity. Instead, contact this office by phone or in writing. ________________________________________ From: Mike Wiliams [[email protected]] Sent: Wednesday, September 14, 2011 2:10 PM To: Teaching in the Psychological Sciences (TIPS) Subject: [tips] Blinded or Blind Studies Hello All. I thought I would take on each of Mike P.'s points: > It should be noted that drug treatment studies can be > conducted with within-subject designs such as crossover designs > where one group receives a drug treatment first and, after a > washout period, receives a placebo treatment. Another group > has placebo first and drug later. In any event, a competent researcher > will make sure that the design they use addresses threats to the > different types of validity involved in the study and try to make > sure that their effect is negated or minimized. >All the patients experience dry mouth and constipation at every cross-over in the design. They all know when the treatment has changed. This does not control for the problem. It might be a somewhat useful to follow the research heuristic that "all treatment/medication studies involving human are invalid" but, as with all heuristics, there will be situations where it fails and situations where it is right but for the wrong reasons. >This is not a heuristic, it is a fact. If the studies are not blinded then they are not valid. They have no internal validity. But if one uses an outpatient population where the participants have no contact with each other, it is hard to see the merit in Williams' critique. >Outpatients still get dry mouth and constipation. (3) A minor point: I would assert that though one's own personal experience is, perhaps, a useful guide to think about things, it does not necessarily constitute a valid guide. It >I was using my own experience as an example. It was also the only way to assess this threat since none of the research studies survey the subjects or investigators. I wonder why? (4) I have conducted the statistical analysis for a few drug studies as represented in the following publications: >Your personal experiences are apparently not relevant (see 3 above). Trying to claim that all studies are invalid or all studies are valid is logically invalid from an inductive perspective -- it is as foolish as claiming that "All swans are white". Those without experience with black swans will swear the "all swans are white" if that has been their lifelong experience. >If it barks like a duck and walks like a duck, it must be a swan. What underlies my criticism is that humans will reason their way through a study and if they are given basic information like side effects, they will infer the presence of treatment or placebo. All the great research guides assume that the subjects are passive agents of the treatment research design. The idea that they would interact with the design causes great problems in our own inferences. I generalize to all studies simply because I cannot think of a way anyone, including myself, can get around the problem. When problems like this exist the very human researchers put their collective heads in the sand and say its not so. We can never be confident that any study of a psychological intervention ever worked. We have to accept that none of these interventions will ever meet an objective standard of empirical support. Constipation trumps all. Mike Williams --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13390.2bbc1cc8fd0e5f9e0b91f01828c87814&n=T&l=tips&o=12657 or send a blank email to leave-12657-13390.2bbc1cc8fd0e5f9e0b91f01828c87...@fsulist.frostburg.edu --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=12658 or send a blank email to leave-12658-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
