The Nocebo Effect
The Nocebo effect has been garnering a lot of attention these days. Its more widely known counterpart, the Placebo effect, occurs when patients’ medical conditions improve on following a procedure or treatment that they expect will make them better, even if they are being administered inactive substances like saline or sugar pills. Placebos, therefore, are used as controls in many drug trials.
The Nocebo effect works on the same principle of expectancy – when patients are made aware of the potential side-effects of a medicine or course of treatment, expecting these side-effects increases the probability that they will actually experience them – even if they are only taking placebos! This is physiologically possible as cognitive, emotional and genetic factors directly influence nociceptive (pain) processing along the pathway from the nociceptor to the spinal cord and the brain.
As a result of this effect, the number of dropouts due to side-effects at clinical drug trials, even amongst groups taking only placebos, are sizable. A recent study conducted shows that close to 11% of the placebo group in fibromyalgia drug trials dropped out because of experienced side-effects such as nausea and dizziness. For cholesterol lowering drugs, discontinuation rates among the placebo group ranged from 4 to 26%. A patient receiving placebos in an anti-depressant drug trial swallowed 26 of them in a suicide attempt. Though the tablets were harmless, the patient’s blood pressure actually dropped life-threateningly.
This effect carries over to real drugs as well. A study was conducted where half the patients were told about a possible side-effect of a certain course of treatment and the other half were kept in the dark about this side effect. Amongst the informed group, 44% of the patients reported that they experienced the side-effect, as opposed to only 15% reporting the side-effect in the uninformed group. Merely expecting side-effects actually increased the likelihood of experiencing them. We can therefore see how medical adherence might be influenced just by the power of suggestion alone.
This of course poses a huge ethical question to physicians – should they inform the participant of the potential complications? Or should they avoid increasing the likelihood that their patients will suffer these complications (as a result of the Nocebo effect) and therefore restrain from mentioning them at all? A patient picks up various cues sub-consciously from the doctor – and just tiny slips in communication, for example “This might sting” might be enough to increase the pain that the patient actually feels. Should Doctor-Patient communication therefore be strictly scripted? Or is the Doctor’s humanness and empathy a part of the evaluation and healing process? If so, where must this line be drawn?
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