Why do some patients not respond to treatment? Is it because of the nocebo effect?
Every day, many of us take clinically proven drugs that fail to work as planned or that trigger unexplained side-effects.
The reasons for this can be chemically complex, but new research suggests that there may also be a far simpler explanation: we think that they are having a bad effect.
It is called the nocebo effect, and it’s the dark side of the well-known placebo effect, when a patient’s health improves because he or she believes that a treatment is going to make them better. The nocebo effect can worsen symptoms, exacerbate side-effects and can render drugs less effective. In other words, expectation of sickness begets sickness.
There are a lot of pessimistic patients: one report suggests that more than a quarter of us may experience the nocebo effect when we take a drug. Researchers from the Cardarelli Hospital, Naples, say in the Journal of Investigational Allergology and Clinical Immunology: “Our data, collected in a large population, confirm that the nocebo effect occurs frequently in clinical practice.” UK doctors agree. “We think that it is a relatively common phenomenon,” says David Blake, Professor of Joint and Bone Medicine at the Royal National Hospital for Rheumatic Diseases, Bath, who has written on the subject.
The positive power of the placebo effect has long been known. According to a report from the University of Mississippi School of Medicine, a study of clinical trials for antidepressants indicates that 40 per cent of people taking the active drug usually feel better, but so do 31 per cent of those taking a dummy pill.
Much less is known about the nocebo effect, and there may even be a biological trigger contributing to it. A paper from Turin University Medical School, in the current issue of Neuro-science, implicates the compound cholecystokinin (CCK), which is involved in pain signalling.
Source - Times