The nocebo effect

The placebo effect is well documented as a contributor to treatment effectiveness in clinical practice. The nocebo effects is less well explained and is known for its undesirable effects, The nocebo effect is potentially underestimated as it is easier to elicit and more impactful than placebo effects.

So what is the nocebo effect? The nocebo effect describes a situation where a negative outcome occurs due to a belief that the intervention will cause harm. Like the placebo effect, nocebo effects are mainly mediated through learning and expectation mechanisms acting through descending pain modulating pathways. Putting it simply, it is the aggravation of pain not due to disease or treatment-inherent factors, but treatment context. Other nocebo effects can include post treatment tiredness or soreness, which are of course very common side effects.

Avoiding the nocebo effect falls down to the patient-practitioner interaction. Your practitioner needs to communicate effectively, consider you as an individual and understand how your pain is impacting your life, empower you to understand and manage your injury. Negative preconceptions of treatment, which can easily create a nocebo effect, are often created by patient social circles or online media. Some patients have occasionally voiced their concerns that treatment will be painful, even before they have sat down. Practitioners should quickly intervene and communicate effectively that patients have complete control in the treatment environment, and any proposed interventions will require their consent.

Many contemporary treatment approaches for pain can be interpreted as the attempt to reduce nocebo effects by creating positive expectations, unlearning of pain conditioning, and addressing psychosocial predictors of long-term pain.

Hohenschurz-Schmidt, D. et al. (2022). Avoiding nocebo and other undesirable effects in chiropractic, osteopathy and physiotherapy.: An invitation to reflect. Musculoskeletal Science and Practice. 62: 102677.