What Sleeping With a Weighted Blanket Does to Your Brain

Weighted vests and blankets have been used for decades to induce calm. But how do they work? Researchers may now have part of the answer. Christian Benedict, an associate professor of pharmacology at Sweden's Uppsala University, had heard of "the magic effects of the weighted blanket"—including purported better sleep and the soothing of anxiety—from "many pediatric doctors and occupational therapists" before deciding to look at the science, per the Washington Post. He asked 26 young men and women to sleep in a lab for two nights, one night with a light blanket (equal to 2.4% of the participants' body weight) and one night with a weighted one (equal to 12.2%), which none of the participants had used before.

Saliva samples taken from the patients between 10pm and 11pm showed a 32% greater increase in melatonin—the hormone produced by the brain's pineal gland in response to darkness as a central part of the sleep-wake cycle—on average when weighted blankets were used. Benedict, lead author of the study published in the Journal of Sleep Research in October, notes weighted blankets mimic pressure from touch and work much like a hug, offering support while allowing for relaxation, per WebMD. According to the Post, deep pressure stimulation is linked to a reduced "fight-or-flight response" and increased "rest-and-digest response."

As the body relaxes, "that signals back to the brain that we are ready to initiate sleep, which is why it boosts the melatonin signal," Benedict tells WebMD. Though people who used weighted blankets in other studies experience a longer duration of sleep, that was not the case here. Researchers say it's unclear whether the observed melatonin boost has therapeutic benefits, but note it could be beneficial for select groups, including children with ADHD and those with melatonin deficiency. "Future studies should investigate whether the stimulatory effect on melatonin secretion remains when using a weighted blanket over more extended periods of time," they note. (More melatonin stories.)