None listed
Conditions
Brief summary
Choice has been found to facilitate placebo effects in acute conditions where standard placebo treatment without choice has failed to elicit a placebo effect. However, it is unknown whether choice can enhance the placebo effect for longer-term treatments where placebo effects are readily established without choice. This study tested whether either a single or daily choice between two treatments enhanced the placebo effect for sleep difficulty relative to no choice and no treatment over a one-week period.
Interventions
Participants were recruited under the guise of a study investigating how attitudes and lifestyle factors can affect adherence to sleep treatment. Participants were then randomised to one of four groups, placebo with daily choice, placebo with single choice, placebo with no choice, or control (see below). All participants that received placebo treatment (lactose capsules) were told that they would receive a sleep medication for 1 week that had been found to be effective for improving sleep qualit
Participants were recruited under the guise of a study investigating how attitudes and lifestyle factors can affect adherence to sleep treatment. Participants were then randomised to one of four groups, placebo with daily choice, placebo with single choice, placebo with no choice, or control (see below). All participants that received placebo treatment (lactose capsules) were told that they would receive a sleep medication for 1 week that had been found to be effective for improving sleep quality. Placebo daily choice - this group was told that they could choose between two different types of sleep medication (actually lactose placebo capsules) each night. One of the supposed medications was described as 'helping to relax the body and induce sleepiness' whereas the other was described as 'preventing feelings of wakefulness and alertness at bedtime'. Placebo singe choice - this group was told that they could choose between two different types of sleep medication (actually placebo capsules) at the start of the treatment period and took that 'medication' for the entire week. One of the supposed medications was described as 'helping to relax the body and induce sleepiness' whereas the other was described as 'preventing feelings of wakefulness and alertness at bedtime'. Placebo no choice - this group was given lactose placebo capsules which were described as either 'helping to relax the body and induce sleepiness' whereas the other was described as 'preventing feelings of wakefulness and alertness at bedtime'. The allocation of the description of the supposed medication in this group was yoked to the decision made by the placebo single choice group.
Sponsors
University of Sydney
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Participants were eligible if they self-identified as having sleep difficulty at least three nights per week on average and were at least 18 years old.
Exclusion criteria
Participants were ineligible if they had received treatment for sleep difficulty in the past three months, were lactose intolerant, or were taking prescription medication other than the contraceptive pill.
Outcome results
None listed