Sunday, May 10, 2009

What is the NOCEBO effect؟

The Nocebo effect is a phenomenon that is simply the opposite of the placebo effect! It occurs when just the expectation of a negative outcome may lead to the worsening of symptoms

Since there are ethical review boards, Nocebo studies have been limited (e.g. An ethics committee would not ever agree to a study that lies to patient that they have a serious disease with a horrible or stressful prognosis ...then sit back and see what happens to them!)

Regrettably natural Nocebo situations do exist and are sadly frequent. Examples include everything from patients self-diagnosing and researching on the Internet their clinical condition, to information on radiological results saying they have cervical DDD or lumbar disc herniations (although irrelevant)

What about when a health care provider says, "you have arthritis, there's nothing you can do about it except live with it!"

This is a very eye opening recent (June 2007) study that supports the nocebo theory where negative verbal suggestions bring on anticipatory anxiety about the potential pain increase

The verbally induced anxiety generated cholecystokinin (CCK), which in turn, assisted pain transmission

Clinical Relevance 1: Many conditions from whiplash-associated disorders, to Parkinson's disease have been found to be affected by Nocebo suggestions

Clinical Relevance 2: How sad that many times, we, the health care providers are the cause of the Nocebo effect ...when we should be focusing on the placebo effect! 

Reference:Benedetti F, Lanotte M, Lopiano L, Colloca L. When words are painful: Unraveling the mechanisms of the nocebo effect. Neuroscience. 2007 Jun 29;147(2):260-71. Epub 2007 Mar 26