The Nocebo Effect

Thomas L. Petty, M.D.

Professor of Medicine, 
University of Colorado

Chairman, National Lung Health Education Program (NLHEP)


National Lung Health Education Program
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The Nocebo Effect

July 1996
PEP Pioneers
Second Wind
Torrance, California

Dear Friends;

Most people, particularly those with a medical illness, have heard of the placebo effect.  Literally, placebo means, “I will please.”  Thus, injections, pills, or elixirs which have absolutely no drug effect can be as beneficial as the drug, itself, such as in pain relief.  If your belief system is anticipating a favorable effect, this is likely to be accomplished by either active drug or no drug.

The nocebo effect is the flip side of the placebo effect.  When patients believe that a disastrous outcome from a medication is about to happen, such as in an impending heart attack, odds are that a heart attack will occur; sometimes it is fatal.  Thus, the notion “scared to death” is really true.

Some cultures believe that a hex can be put on people and that harm will follow.  These same cultures go to great lengths to exorcize or otherwise neutralize this hex and the consequences that are predicted to follow.  In our culture, we can use “the power of positive thinking”, as Norman Vincent Peale popularized, to counteract the nocebo effect.

Depression is the mother of the nocebo effect.  Hope and faith are the fathers of the placebo.  Hope and faith have been proven to slow the progress of breast cancer and reduce symptoms in controlled scientific studies.  Hope and a healthy attitude about life can sustain many people with severe impairments.

I was reminded of this vividly at the 16th Annual Rally held in Torrance on the last day of May.  The many smiling faces of several hundred people with various stages of COPD, often quite advanced and requiring oxygen, was an uplifting experience for all who were there.  There was no sign of the nocebo jinx.  Hope and humor presided.  Nocebos are not for me and certainly not for you.

I’ll be in touch next month.

     Sincerely yours,

    Thomas Petty, MD

Last update:
9 April 2002