Case Study: Weighted blankets have significant effects on indviduals suffering from insomnia

This scientific study published in the Journal of Sleep Medicine & Disorders shows positive results from using the Somna Chain Weighted Blanket for people with sleeping problems. This summary was compiled by Somna AB. 

Ackerley R, Badre G, Olausson H (2015), Positive Effects of a Weighted Blanket on Insomnia. J Sleep Med Disord 2(3): 1022.

Insomnia is a common occurrence in today’s society and can have a negative impact on physiological, psychological and social well-being. There is therefore a need for simple, effective solutions to increase sleep quality. Since weighted blankets have been demonstrated to provide a beneficial calming effect in several clinical disorders, in young and older people alike, we deemed it of interest to investigate the effects of using a weighted blanket on people with insomnia.
The study looked at the effects of the Somna Chain Weighted Blanket in 31 subjects (11 men and 20 women) who suffer from insomnia. The level of insomnia and any daytime tiredness and sleepiness in the participants were assessed using two well-known assessment scales: the Insomnia Severity Index (ISI) and the Epworth Sleepiness Scale (ESS).
The participants were monitored over four weeks. For the first week they slept as usual, while during weeks two and three they slept with a Somna Chain Weighted Blanket™ weighing 6, 8 or 10 kg. During the final week they once again slept as usual without a Somna Chain Weighted Blanket.
The study took both objective and subjective measurements. Objective measurements were taken throughout the period (four weeks), partly by asking participants to wear an actigraphy watch, which continuously measured their activity and sleep quality both day and night. Objective measurements also included polysomnography (PSG). In the first week (sleeping without the Somna Chain Weighted Blanket) and at the end of the third week (sleeping with the Somna Chain Weighted Blanket), the subjects’ night’s sleep was registered using PSG. PSG entailed the participants sleeping as usual at home in their beds, while electrodes attached to their bodies registered and measured several variables simultaneously, such as brain and heart activity, muscle activity, breathing, blood oxygen levels and eye movements. Finally, body movements were also registered and analysed in a special way using a soft sensor pad placed under the sheets.
Subjective measurements were also taken throughout the test period. Over the four-week period, all the participants kept a sleep diary, reporting their sleep quality using a Visual Analogue Scale (VAS). They also completed a questionnaire every day, in which they assessed how refreshed they felt on awakening and their perception of well-being and tiredness during daytime according to the Karolinska Sleepiness
Scale (KSS). At the end of the four weeks, the participants also answered questions about their experience of sleeping with and without the Somna Chain Weighted Blanket. They also assessed the Somna Chain Weighted Blanket’s other properties such as warmth, weight and comfort.
The subjective results showed that the participants liked sleeping with the Somna Chain Weighted Blanket. They felt that it was easier to settle down to sleep, and that they slept better. They also said they felt more refreshed in the morning.
Objectively, the study found that the sleeping period increased, and that movements during sleep decreased when participants slept with the Somna Chain Weighted Blanket, see the diagram below:
The figure shows significant differences between measurements with the Somna Chain Weighted Blanket and without, with regard to the actigraphy watch. A) The sleeping period (sleep bout time) increased.
B) Movement (activity) decreased while participants were in bed. C) Movement (activity) decreased significantly during the night’s sleep.
In summary, the researchers found (both objectively and subjectively) that the participants could sleep more calmly when they used the Somna Chain Weighted Blanket.
A Somna Chain Weighted Blanket can in many cases help people with insomnia, perhaps not only due to its weight but through the tactile stimulation provided by its two-in-one function. It could be a non-pharmacological approach and complementary tool to improve sleep quality.
The study was presented at The World Sleep Congress of the World Sleep Federation, in Istanbul, 31 October – 3 November 2015. Please contact Somna to request the full study.

Read the full study here:

Kingkraft are the UK Distributor of the Somna range of weighted products. We are proud to offer the full range of items on a loan basis to enable you to try before you buy! Find out more information here. Should you have any questions simply speak to a member of the team on 0114 2690697 or email


The Kingkraft Team