Posted by Deahoidar on December 3, 2015, at 0:10:21
In reply to Re: Ketamine Nasal Spray Deahoidar, posted by Meltingpot on December 1, 2015, at 10:07:30
> I don't understand though why you say "It also lends support to the possibility that the placebo effect could play a significant role in the "successes".
>I'm no expert on advanced statistical analysis or the various theories regarding the power of placebo. So, my understanding and comments are derived from scientific journal publications and statements by professional DBS researchers.
It has been shown that placebo surgery will seem to be more effective than a placebo pill. i.e. the magnitude of the placebo response varies according to its supposed potency. (It's easy to imagine how DBS as a "treatment of last resort" could foster considerable placebo response)
There are also placebo-enhancing effects that may be associated with treatment. e.g., the effect of informed-consent procedures, the effect of medical and nursing care, and even the patient-doctor relationship -- these can all contribute to a patient's perception of clinical benefit.
A good randomized controlled trial seeks to ensure that these factors and effects are similarly distributed. That's one of the reasons why multiple study sites are incorporated.
Literature on placebo effect has repeatedly reported prominent placebo effects are found in 3 neurological disorders: pain, depression, and Parkinson's disease. Antidepressant drug trials have revealed that 35% of patients receiving placebo show improvement. Some authors suggest the overall effect is even higher.
As for DBS as treatment for depression, an editorial in the Journal of Neurosurgery observed that open-label studies of DBS "cannot be regarded as evidence of efficacy. A 29% improvement rate at 1 year is modest and may be consistent with a placebo response."
The American Academy of Neurology (AAN) reported on the significant failures of 2 large scale clinical trials for DBS, with a prominent researcher saying "The bottom line is that we can't separate out active treatment from placebo... it's bad news for DBS." It was also reported that the placebo response in one clinical trial was approx. 25%. That's not a lot, but it wasn't significantly different from the actual treatment. They couldn't tell them apart. Some believe the failure of these clinical trials may mean the end for this DBS technology.
So that's my understanding. Despite tremendous treatment-resistance, some patients are still able to produce significant placebo response. If they improve, that's great! But before a treatment is marketed as effective, it has to be proven.
poster:Deahoidar
thread:1083978
URL: http://www.dr-bob.org/babble/20151119/msgs/1084344.html