The Influence of a Placebo, Body Position and Medication on Motion Sickness

Placebo Interventions for Nausea: a Systematic Review

“…Of the nine instructional manipulations to reduce or induce nausea, five experimentally induced nausea through rotation [21,22,49,50,52], two concerned nausea resulting from exposure to a naval cruise [47,48], and two clinical studies examined the effect of manipulating expectancies in chemotherapy patients [30,51]. Six of these studies attempted to reduce nausea [21,30,47,48,51,52], one attempted to induce nausea [22], and two experiments aimed to both induce and reduce nausea in different groups of participants [49,50].…”

“…Six of these studies attempted to reduce nausea [21,30,47,48,51,52], one attempted to induce nausea [22], and two experiments aimed to both induce and reduce nausea in different groups of participants [49,50]. Instructional manipulations were brief and usually spoken rather than written.…”

“…Nausea was assessed using a combination of self-report and objective outcomes. All nine studies elicited symptom ratings, although for one field study this was achieved through interview with a blinded observer post naval cruise [47]. Three of the five rotation studies included rotation tolerance, a behavioural assessment reporting the time a participant can withstand rotation [21,22,52], with two of these also including another behavioural assessment in recording the number of head movements participants made [21,52].…”

“…Tyler [47] The groups of troops that received a placebo pill had the same incidence of moderate or severe sickness than untreated controls. This held across a further three replications.…”

“…Shortly after World War II, Tyler [47] found that supplying troops with placebo pills just before they embarked on amphibious training did not decrease the proportion who experienced moderate or severe seasickness relative to those given no treatment. Although there was no statistical analysis performed on this data, a chi-square analysis of the reported values in the original article show no effect of placebo treatment, χ 2 =1.37, p>0.05.…”