(CNN) After my sister gave me a weighted blanket for Christmas, it became the gift that I didn't know I needed. It's one of the best things ever to happen to me.
As someone with anxiety, I've struggled with restful sleep: Falling asleep can take up to two hours, or I wake up at least twice during the night.
The first night I started sleeping underneath a 15-pound weighted blanket, I slept straight through the night for the first time in months and felt more rested during the day. After a few days of good sleep, I learned that my sister had done her gift research — she had read that people with anxiety tended to feel more grounded when using the blankets.
Fascinated, I asked experts on mental health and sleep to explain why these heavy blankets — which are filled with plastic, glass or metal particles and layered with extra fabric — have eased the, ahem, weight of some people's anxiety-related sleep struggles.
Weighted blankets, which range from 5 to 30 pounds (2.27 to 13.6 kilograms), have been used by special needs educators and occupational therapists since the late 1990s, but have become mainstream in the last few years. Regular blankets can weigh around 3 to 5 pounds.
The dominant theory is that weighted blankets provide deep pressure stimulation, a feeling that resembles a "firm, but gentle, squeeze or holding sensation and ... triggers these feelings of relaxation and of being calm," said pulmonary and sleep specialist Dr. Raj Dasgupta, an assistant professor of clinical medicine at Keck School of Medicine at the University of Southern California. Feeling relaxed is what decreases cortisol, a stress hormone that typically runs high in people with chronic anxiety, stress and other disorders, he added.
There is evidence suggesting that deep pressure stimulation reduces sympathetic nervous system arousal — that's our fight-or-flight response — and increases parasympathetic activity, which may cause the calming effect, said Dr. Fariha Abbasi-Feinberg, the director of sleep medicine at Millennium Physician Group in Florida.
Pressure to stimulate the sensation of touch to muscles and joints is the same proposed mechanism behind massage and acupressure, added Abbasi-Feinberg, who is also a neurologist on the American Academy of Sleep Medicine's board of directors. "This calming (effect) can promote better quality sleep."
If you're interested in using a weighted blanket to aid sleep problems related to mental or sensory disorders, here's what you should know about their effectiveness, any caveats and how to choose one.
Weighted blankets have been growing in popularity, but there isn't actually much research on their effectiveness. That may be due to the newness of weighted blankets, their relative harmlessness and that other health issues are more urgent for researchers to study, Dasgupta said.
Some people with anxiety, depression, bipolar disorder or insomnia have reported improved quality of sleep and feeling more restful during the day, a few recent, small studies have found. Many study participants experienced a decrease of 50% or more in their Insomnia Severity Index scores after using a weighted blanket for four weeks, in comparison to 5.4% of the control group, according to a small study published in the Journal of Clinical Sleep Medicine last September.
In the follow-up phase of the study, which lasted one year, people who used weighted blankets continued to benefit. People who switched from lightweight control blankets to weighted blankets experienced similar effects. And those who used weighted blankets also reported better sleep maintenance, a higher daytime activity level, remission from insomnia symptoms and alleviated symptoms of anxiety, depression and fatigue.
Researchers who studied the effects of weighted blankets on children with attention-deficit/hyperactivity disorder or autism have found either some positive associations or no associations with better sleep or reduced symptoms.
"A 'grounded feeling' due to the use of weighted blankets may be attributed to the psychoanalytic 'holding environment' theory, which states that touch is a basic need that provides calming and comfort," Abbasi-Feinberg said via email. "Weighted blankets are designed to work similar to the way tight swaddling helps newborns feel snug and secure."
Many, if not all, of the available studies on weighted blankets used participants who had a psychiatric, developmental or sleep disorder such as anxiety, depression, autism, ADHD or insomnia. That's likely because of "the fact that these segments of the population are the ones who could benefit most from touch- or sensory-related therapies," Abbasi-Feinberg said.
However, given how weighted blankets might work to reduce cortisol levels, they could help to reduce general stress, too, Dasgupta said.
People have shared their fondness for weighted blankets in studies and online, but people with the same psychiatric disorders may not have the same relaxing experiences with weighted blankets. One person in the follow-up phase of the 2020 study discontinued their participation due to feelings of anxiety when using the blanket. People who are claustrophobic may also not fare well. More studies on factors that make individuals more or less helped by weighted blankets are needed, Dasgupta added.
A weighted blanket's calming abilities may help to regulate breathing, but some health professionals are hesitant to recommend weighted blankets to people with obstructive sleep apnea, asthma or other respiratory conditions. "You'd have to be pretty brittle and pretty sick if a blanket's going to stop your breathing," Dasgupta said. But if you're not sure, he added, be careful and talk to your pulmonologist first.
Children should be assessed by occupational therapists or pediatricians before they try weighted blankets, as many weighted blankets haven't been tested for the effectiveness and safety for children.
"Weighted blankets shouldn't be used for toddlers under 2 years old, as it may increase the risk of suffocation," Abbasi-Feinberg said. "It's important for parents to always consult their pediatrician before trying a weighted blanket."
Dogs sometimes benefit from pressure-applying garments during storms or other anxiety-inducing events, but weighted blankets can be dangerous for pets, said Dr. Douglas Kratt, president of the American Veterinary Medical Association.
"For smaller or elderly dogs, weighted blankets may be too heavy, restricting your pet's movement in potentially dangerous ways," he added. "If your pet is a chewer, the contents of these blankets could also pose a choking risk or, if ingested, cause a gastrointestinal obstruction."
Discuss possible behavior modification plans with your veterinarian first.
If you're looking for a weighted blanket, there are multiple options in terms of weight, materials and size. A blanket that weighs 7% to 12% of your body weight is typically the range to choose from, but that may depend on personal preference. "Some individuals might want a heavier weight to feel a sense of 'hugging' and calmness, while others might want something lighter," Abbasi-Feinberg said.
And there are weighted blankets for year-round use, she added — some are made with a higher proportion of fabric layers made from cotton, which is lighter than other materials and allows air to pass through its fibers, therefore better managing your body temperature.
Dasgupta thinks of sleep as a puzzle, and sometimes people with insomnia or mental disorders are missing some of the pieces needed for great sleep, but "no one really knows what puzzle pieces are missing."
Weighted blankets could help, but they're not a cure-all — a healthy sleep routine is still necessary for getting enough of both sleep time and the deeper stages that leave you refreshed. If you think that a weighted blanket could be your missing puzzle piece, "it's worth a try," Dasgupta said. The downside is that these blankets can be pricey.
During the pandemic, "sleep really took a hit" when it comes to insomnia, altered circadian rhythm and nightmares, Dasgupta said. "A weighted blanket is something that might have a role during this pandemic. ... That sense of the basic need to be touched and hugged could actually provide some comfort and security. Maybe that's why some people benefit from a weighted blanket."