Purpose of review: This article addresses nocebo in headache. Nocebo is the antipode of placebo and refers to adverse events a person manifests after receiving placebo.
Recent findings: In randomized trials for migraine prevention meta-analyses revealed that eight out of 20 patients treated with placebo experienced any adverse event. More importantly, one out of 20 patients treated with placebo withdrew treatment because of adverse events. The adverse events in placebo groups mirrored the adverse events expected of the active medication studied, confirming that pretrial suggestions induce the adverse events in placebo-treated patients. Nocebo was higher in preventive treatments than in symptomatic ones. Among preventive migraine treatments botulin toxin A showed the lowest nocebo. Generally, the safer a drug was the less nocebo was induced. Nocebo was similar in trials for tension-type headache. To predict and prevent nocebo consequences a 4-item self-fulfilled questionnaire (Q-No) has been developed, with 72% specificity and 67% sensitivity.
Summary: Although nocebo remains largely unknown in the medical community, it limits adherence and treatment outcomes significantly in preventive treatments for migraine and tension-type headache. The Q-No questionnaire may help in predicting nocebo, whereas individualized strategies are needed to prevent nocebo consequences.