Hello All. When I was a grad student, we were conducting a clinical trial of Imipramine vs Xanex in the treatment of severe depression. The study was conducted on an inpatient research unit in the hospital. The patients lived there and I noticed that they would sit in the day room in the evenings and discuss their treatment. Although the medications were assigned randomly and the researchers did not know the assignment, the patients with dry mouth and constipation knew they were taking the medications. Those given placebo knew this because they did not suffer constipation and dry mouth (the anticholinergic side effects). The patients knew which treatment they were receiving and they communicated this to the investigators because the investigators constantly monitored the side effects. The constant monitoring of side effects unblinds the study.
This happens in every clinical trial of psychotropic medications. This problem is even more obvious in every clinical trial of psychotherapy. All these studies are invalid. I could explain why they are invalidated by referring to the gigantic literature on expectation biases. Since all the dependent measures involve a judgement by the patient or the investigator that the disorder got better or worse, they are all influenced by the expectation bias that the treatment worked. I think many subjects want to help the researchers and they endorse small positive changes on the dependent measures. The people who get placebo behave consistent with this because they know they never got treatment. All the investigators have to do is anonymously survey the subjects. The results will blow their minds. To my knowledge, this obvious, simple assessment has never been made. Now you may be able to understand why the treatment effect size today for antidepressants is the same as the placebo effect for some studies in the past - its all noise. Mike Williams ______________________________________________________ Hi Mike: This is a very interesting point but I am not sure that I follow the argument completely. Please expand your argument, dotting the 'i's and crossing the 't's. Ken On 9/12/2011 3:00 AM, Mike Wiliams wrote:
Clinical Psychology psychotherapy and psychotropic medication therapies will never have sufficient empirical support simply because the subjects are never blind to the treatment condition.
************************* All the
investigators are doing is training the subjects to endorse change on the dependent measures.
************************** That's why the meta-analyses conclude that
any therapy is effective. I have never seen an analysis that addressed this research problem. It's similar to the obesity researchers who never notice that their entire field is based on the dieting behavior of young women. Mike Williams Drexel University
--------------------------------------------------------------- Kenneth M. Steele, [email protected] Professor Department of Psychologyhttp://www.psych.appstate.edu Appalachian State University Boone, NC 28608 USA --- 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=12612 or send a blank email to leave-12612-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
