Abstract Details

Title Investigating the Placebo/Nocebo Responses and the Natural History of the Disease in Patients with Migraine

Topic Headache

Presentation(s) P01 - (-)

Poster/Presentation
Number 080

Objective

Background In RCTs of antimigraine drugs, a positive response to placebo was observed in 1/3 of migraineurs. Unfortunately, all these studies cannot distinguish between real placebo responses and spontaneous remission of symptoms. In addition, the nocebo response has not been adequately investigated.

Design/Methods 1556 migraine patients were involved in the study. 984 migraineurs (256 men, 728 women, mean age ± SD = 38.2 ± 13.8 yrs) received a tablet containing talcum powder. According to the presence or absence of headache at the time of visit, they were told that the pill might produce reduction or disappearance of pain (placebo) or appearance of pain (nocebo). 572 migraineurs (158 men, 414 women, mean age ± SD = 39.7 ± 12.3 yrs) were used as controls, evaluating the spontaneous remission of symptoms without receiving any treatment (natural history). The presence/absence of headache in the 4 hours after the test was recorded.

Results A placebo positive response was observed in 36% of migraineurs, while a nocebo positive response was reported by 16% of cases. In the no-treatment group, a reduction of pain was observed in 21% of subjects, while appearance of pain was observed in 17% of subjects. Hence, the "true" placebo effect was 15%. In addition, the reduction of symptoms in migraine without aura patients was significantly higher than that observed in migraine with aura patients (p<0.01).

Conclusions Our study shows that in migraineurs a true placebo effect can be distinguished from the natural history effect. This is the first study finding evidence that placebo has a true powerful clinical effect in migraineurs. RCTs in migraine patients should consider this interesting phenomenon in the planning of the study and in evaluating side-effects of the pharmacological treatment.

Authors/Disclosures
PRESENTER	No disclosure on file
	No disclosure on file
	No disclosure on file
Paola De Martino, MD, PhD	No disclosure on file
	No disclosure on file
Lorenzo Pinessi, MD (University of Turin/Dept of Neuroscience)	No disclosure on file
Innocenzo Rainero, MD, PhD (University of Turin)	No disclosure on file
Kathryn A. Giles, MD	No disclosure on file

��ɫ��

��ɫ��