[Guest]

Dr.,

How is it that placebos are so effective in depressive and anxiety disorders? When I look at response charts for various antidepressants, I see that although the actual drug is more effective, placebo responses are quite effective as well. Even the timeline of improvement is similar, the placebos seem to show the greatest improvement after about 4 weeks, just like the antidepressants. I have even seen 6 month studies and the placebo seems to actually be holding up quite well in those studies as well.

I can't help but wonder, how can they be so effective, and have a response along the same timelines as anti-depressants? No other type of illness shows such a dramatic response to pacebo, it almost makes the antidepressants look like placebos "with a kick". If these disorders are considered to be significantly biologically based, how can a placebo illicit such a response, and, at least when averaged across the population taking it in the study, show sustained improvements from baseline?

Thanks as always.

[Guest]

Furthermore, the PET scan changes of the brain of a responder are similar whether you respond to placebo or active medication. In fact, some people point to studies where antidepressants work the same as placebo. Invariably in these studies, it is not that the antidepressants are ineffective, it is that the placebo is so extremely effective. It may be that there is a different population that is less ill and respond to placebo quite well. Conversely, it may be that placebo is not a bad treatment (but not FDA approved) for depression. It even may be effective (a few studies) when you tell a patient they are getting placebo. There is no doubt that when you change your mind, you change your brain and vice versa. There actually are many other conditions with a fairly powerful placebo response from pain to warts. Why placebo should be effective is unknown.
[quote] Dr. ,

How is it that placebos are so effective in depressive and anxiety disorders... [/quote]