(Reuters Health) - People with insomnia who take placebos, or “dummy pills,” may feel more rested than patients who get no treatment at all, a review of sleep research finds.
Previous clinical trials testing sleep drugs like temazepam (Restoril) against placebo pills have found insomnia symptoms can improve even when patients don’t get the real treatment, said senior study author Dr. Ben Colagiuri of the University of Sydney in Australia. One problem with using placebos in these trials, however, is that sometimes simply taking part in a study can influence how people perceive their symptoms, he said.
To solve this issue, Colagiuri and colleagues examined data from 13 previously published studies that assigned some insomnia patients to receive a placebo they were led to believe was an active treatment or to a control group that got no treatment.
Compared to participants who didn’t receive any treatment, those who got placebos they believed were real treatments reported more improvements in their ability to fall asleep, total amount of rest and sleep quality, the analysis found.
“The comparison with no treatment means that we can be sure that the improvement we observed was due to a genuine placebo effect, rather than being an artifact of simply taking part in a trial,” Colagiuri said by email. “The study provides new evidence that genuine placebo effects exist for insomnia treatments.”
Combined, the studies used in the analysis had a total of 566 participants who either reported that they had insomnia or had the condition diagnosed by a clinician.
It’s unclear exactly why the placebo might help some people feel better rested, but it’s possible just the act of taking a pill eased some anxiety that made it harder for people to fall asleep, Colagiuri said. Some recent research in other conditions like migraines and chronic pain suggests the placebos may help even when people know they’re taking dummy pills, he added.
However, when researchers examined data on 103 participants who had objective tests like sleep-phase monitoring to measure how quickly patients fell asleep with a placebo or without treatment, they didn’t find any significant difference between these groups.
Beyond the small number of total participants, another limitation of the current study is that researchers didn’t have objective measurements of sleep quality or duration to compare placebos against no treatment, the authors note in Sleep Medicine.
Still, the results make sense because insomnia is ultimately a disorder of perception, said Patrick Finan, a psychiatry and behavior researcher at Johns Hopkins University School of Medicine in Baltimore.
For example, a person who reports typically getting only four hours of sleep a night, for example, might not meet the criteria for insomnia if they don’t feel like the lack of rest impairs their mood, cognition or behavior, Finan, who wasn’t involved in the study, said by email.
By contrast, a person who says they normally get seven hours a night might still have insomnia if they feel like they the amount or quality of sleep they get is inadequate and they also report daytime impairments in work or home life that they attribute to a lack of sleep, Finan added.
“The upshot is insomnia is shaped by expectation and perception, so it is not surprising that placebos, which implicitly alter expectation, are effective in improving perceptions of sleep,” Finan said. “It is notable that the effects of placebos did not extend to objective measures of sleep.”
SOURCE: bit.ly/2pG6feK Sleep Medicine, online April 3, 2017.