What is the current thinking on the placebo effect?

In this column, SDSTAFF David writes that a 2001 study suggested that the placebo effect may not be true. Instead, some people just get better because of the uneven course of disease. What is the latest on the placebo effect? Is there still broad consensus that the brain changes our physiology such that some people will cure diseases with a sugar pill and positive thinking?

As a related question that may be easier to answer, is there a placebo effect in animals?

The debate rages on:

Scientific American February 20, 2004: http://www.sciam.com/article.cfm?articleID=000B6140-F61E-1034-B61E83414B7F0000

The evidence in animals is sketchy at best, but:

Jæger, *et al. * “Stratification, Blinding and Placebo Effect in a Randomized, Double Blind Placebo-controlled Clinical Trial of Gold Bead Implantation in Dogs with Hip Dysplasia,” *Acta Veterinaria Scandinavica * 2005, 46:57-68 http://www.actavetscand.com/content/46/2/57

and

McMillan, “The placebo effect in animals,” 1999 Oct 1;215(7):992-9: http://www.ncbi.nlm.nih.gov/sites/e...6&dopt=Citation (There isn’t even an abstract available on this one; it’s a review article, so it could actually say that any previous studies showing a placebo effect in animals were flawed).

and

http://www.sciencemag.org/cgi/content/abstract/138/3541/677

Don’t tell me the placebo effect doesn’t exist! I’ll never get better now that I know about it.

Then I definitely won’t tell you about the Nocebo Effect: http://www.washingtonpost.com/ac2/wp-dyn/A2709-2002Apr29