Posted by SLS on August 13, 2008, at 22:16:49
In reply to Re: Placebo in Psychiatric Clinical Trials, posted by bleauberry on August 13, 2008, at 19:13:45
> A %: Were about to spontaneously improve anyway. It coincidentally happened at that time.
My guess is that this happens only occasionally.
> B %: Got a brain jolt from the excitement of talking with the researchers and going through the whole process and anticipation. It's a big deal, lots of attention and care, got a nice adrenaline boost in it all.
I believe this is possible, but not probable.
> C %: The power of the mind. A true placebo response.
This is a point of contention. Aren't all responses during placebo administration true placebo responses?
> D %: Started sleeping better, eating better, not worrying so much, more energy, now relieved that they are involved in something with hope and promise. So the scores relating to those specific questions on the DSM questionnaire improved to a point that showed a significant overall DSM total score reduction. But, hidden by statistics is that on the other DSM questions about depressed mood and lack of interest in pleasure, they were still severely depressed. The other improved scores relating to sleep, energy, and eating overshadowed that and made it appear falsely that they had improved.
This is very astute.
> E %: Human error. As smart as we think we are, we do not do anything perfect.
> F% : Hidden human subjectivity, politics or economics.
I think you touched on a very important point. Placebo administration in a clinical setting is not equivalent to "no treatment". The patient is shown a great deal of attention and support. Batteries of tests and a more focused diagnostic procedure captures trust. The patient is convinced that they are getting the best care possible, and finds emotional relief. He becomes optimistic and animated. When questioned how he feels, the patient often replies "better" and will even score better on psychometric tests. Even the socialization that occurs with the investigative staff provides a therapeutic psychosocial intervention for patients who are generally isolating.
Clinical trials usually don't run beyond 8 weeks. As such, these investigations are not longitudinal. It seems that when followed up for longer periods, placebo responders relapse at a much greater rate than drug responders.
Charles Nemeroff on Medscape (registration is free):