Some people have trouble sleeping because they have too much on their mind. The solution may be to add more to their body. That’s because researchers in Sweden found study participants reported significantly reduced insomnia severity, better sleep maintenance, a higher daytime activity level, and reduced symptoms of fatigue, depression and anxiety when sleeping with a weighted chain blanket.
A weighted chain blanket is a blanket that gets its weight from metal chains which have been sown in. Researchers published their findings in the Journal of Clinical Sleep Medicine and expressed a belief the blankets provide stimulation to the nervous system and foster a feeling of calmness.
"A suggested explanation for the calming and sleep-promoting effect is the pressure that the chain blanket applies on different points on the body, stimulating the sensation of touch and the sense of muscles and joints, similar to acupressure and massage," said principle investigator Dr. Mats Alder, consultant psychiatrist in the department of clinical neuroscience at the Karolinska Institutet in Stockholm, Sweden. "There is evidence suggesting that deep pressure stimulation increases parasympathetic arousal of the autonomic nervous system and at the same time reduces sympathetic arousal, which is considered to be the cause of the calming effect."
Study participants had a mean age of 40 years and the group of 120 was comprised of 68 percent women and 32 percent men. All had been previously diagnosed with clinical insomnia and a co-occurring psychiatric disorder such as bipolar disorder, major depressive disorder, attention deficit hyperactivity disorder or generalized anxiety disorder.
The blankets used in this study weighed 18 pounds. However, some thought that was too heavy and opted for 13-pound blankets instead. The control group used blankets with light plastic chains that weighted just over three pounds.
Researchers used the Insomnia Severity Index (ISI) to measure the amount of insomnia and participants used a wrist-worn device to estimate sleep and daytime activity levels. Close to 60 percent of the participants had a decrease in their ISI score of 50 percent or more compared to 5.4 percent in the control group. Just over 42 percent of the study group achieved remission of insomnia according to the ISI scale compared to 3.6 percent in the control group.
The study lasted four weeks but the participants had the option to use the blankets during a 12-month follow-up phase which continued to show positive results. Those in the control group had the option to switch to the weighted blanket and they experienced similar results to those who were initially given the weighted blanket. One person opted out of the study stating the blanket heightened their feelings of anxiety but of the 92 percent who responded after 12 months, 78 percent were in remission for insomnia.
"I was surprised by the large effect size on insomnia by the weighted blanket and pleased by the reduction of levels of both anxiety and depression," said Adler.