CNN: Weighted blankets, which range from 5 to 30 pounds, 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.

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