Weighted blankets may lead to more melatonin, the sleep hornone
“I met many pediatric doctors and occupational therapists who told me about the magic effects of the weighted blanket, but we don’t know if it acts as a placebo or what,” said study author Christian Benedict, associate professor of pharmacology at Uppsala University in Sweden. “This was one of the reasons I decided to do this study.”
In the study, 26 young men and women with no sleep problems or other medical conditions were asked to sleep in the laboratory with a weighted blanket one night and a light blanket another night. None of the participants had a history of using weighted blankets. The weighted and light blankets corresponded to, respectively, 12.2 percent and 2.4 percent of each person’s body weight.
The researchers took saliva samples every 20 minutes between 10 p.m. and 11 p.m. to measure changes in hormone levels. On average, the rise in melatonin was 32 percent greater on the night the participants slept with a weighted blanket.
“Body sensations, including gentle pressure on the skin, can activate brain regions that can influence the release of melatonin,” Benedict said. “We believe that a similar mechanism accounts for the observed rise in melatonin when using a weighted blanket.”
Weighted blankets have weights such as metal chains or glass beads sewn into them, along with traditional stuffing, to apply even, deep pressure to the body. Occupational therapists in the 1990s discovered that weighted vests and blankets had a calming effect on children and adolescents with developmental and sensory disorders. They later were used in adult mental health settings as a humane alternative to restraint and seclusion, which are known to cause physical and psychological harm to patients.
The concept of deep pressure stimulation goes back even further, explored most notably in the 1980s by American scientist Temple Grandin, who has autism and designed a Hug Machine as a way to relieve her anxiety. It worked by gently squeezing her with padded boards. Other examples include swaddles for babies and anxiety vests for dogs, both used in a way similar to hugs to induce calm.
Applying a gentle pressure across large swaths of the body activates the autonomic nervous system, which regulates heart rate, digestion, breathing rate and other functions. Specifically, deep pressure stimulation is associated with reduced sympathetic arousal, or fight-or-flight response, and increased parasympathetic arousal, or rest-and-digest response.
Research has suggested that deep pressure stimulation from weighted blankets, in particular, may improve sleep. In 2020, Håkan Olausson, a neuroscientist at Linköping University in Sweden, and his colleagues performed a randomized controlled trial of 120 patients with psychiatric disorders, giving them a weighted blanket every night for two weeks. The patients reported less severe insomnia, reduced daytime fatigue and better sleep maintenance throughout the night when sleeping with a weighted blanket vs. a light blanket.
A 2015 study tested weighted blankets on 33 people with chronic insomnia, reporting that they slept longer, found it easier to settle down, and felt more refreshed in the morning. And a study on two children with autism spectrum disorders demonstrated improved quality of sleep with weighted blankets.
“Weighted blanket use has increased dramatically in the last few years, but most studies have limited sample sizes,” said Cara Koscinski, occupational therapist and co-author of “The Weighted Blanket Guide.” “We cannot jump to big conclusions,” about the latest study, she said, but the observed melatonin increase “provides another piece of the puzzle.”
“This is a very interesting study, but it would be nice to see it replicated in a second cohort because it is not an obvious thing that melatonin should increase with a weighted blanket,” Olausson said.
Benedict supported the need for larger trials, including, he said, “an investigation of whether the observed…
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