Weighted blankets for better sleep

Relation

Ekholm B, Spulber S, Adler M. A randomized controlled trial of weighted chain blankets for insomnia in psychiatric disorders.J Clin Sleep Med. 2020;16(9):1567-1577.

Study objective

The aim of this study is to evaluate the use of weighted blankets to improve sleep in people with a variety of psychiatric illnesses.

Draft

A randomized, controlled, blinded trial in Stockholm County, Sweden

Participant

Study participants included 120 patients diagnosed with insomnia and one of several psychiatric disorders: major depressive disorder (38%), bipolar disorder (40%), generalized anxiety disorder (11%), or attention deficit hyperactivity disorder (11%). There was no effort to focus on 1 gender; However, 68% of participants were women. The average age was 40 years, with a range of 18 to 77 years. The average duration of insomnia was 20.2 years (SD 15.0). The majority of patients were treated with medication, and researchers instructed them not to change their medications during the study. Medication use included: hypnotics (37%), sedatives (33%), lithium (20%), anticonvulsants (14%), antipsychotics (23%), antidepressants (53%), and stimulants (9%).

intervention

Half of the participants were randomly assigned to the weighted blanket condition, which provided an 8 kg (17.6 lb) metal chain blanket. When participants initially tried the blanket in the clinic and found it too heavy, they were given a 6kg blanket instead. The control blanket consisted of a plastic chain of the same size and shape as the metal, giving a total weight of 1.535 kg (3.4 lb). One patient withdrew early and reported an increase in anxiety with the weighted blanket. Researchers assessed insomnia severity after 4 weeks. At this point, the study opened for the following 12 months, with participants either continuing with the weighted blanket or switching to it if they were previously in the control group. They had the opportunity to choose from 4 blankets (2 chain blankets weighing 6 or 8 kg or 2 ball blankets weighing 6.5 or 7 kg). The majority (112 people) continued in the study throughout the study, and the 7 who opted out were included in the final analysis.

Study parameters assessed

The primary outcome was sleep disturbance, assessed using the Insomnia Severity Index (ISI), an established self-report tool. The ISI has 7 items that are summed and interpreted as ≤7 (meaning no insomnia), 8–14 (meaning subthreshold insomnia), 15–21 (moderate insomnia), and ≥22 (severe insomnia). Secondary measures focused on daytime symptoms and activity levels. These included actigraphy, the Fatigue Symptom Inventory, and the Hospital Anxiety and Depression Scale.

Key insights

Researchers assessed participants for response and remission of their symptoms according to the ISI score. The authors defined response as a decrease in ISI score of 50% or more from baseline and remission as ISI ≤7. At the initial assessment after 4 weeks of use, in the weighted blanket group, 59.4% had responded (versus 5.4% of the control group) and 42.2% were in remission (versus 3.6% of the control group). Over the 12-month continuation, the therapeutic effect increased, with 92% of all first-time participants responding and 78% in remission. Objective measurements using actigraphy showed no significant effects on sleep parameters, although participants subjectively reported improved sleep retention. Improvement in insomnia was 26 times greater with the use of a weighted blanket than with the control blanket.

Deep pressure also increases oxytocin. Oxytocin promotes relaxation, security and sleep.

Daytime function improved significantly in those who used the weighted blankets. Subjectively, the Fatigue Symptom Inventory improved. Objectively, there was an overall increase in daytime activity as captured by the actigraph, and the peak of activity occurred later in the day.

Further analyzes compared responders (an ISI decrease of >50%) with nonresponders (<50% ISI decrease). Responders showed a significant improvement in subjectively reported sleep maintenance and a decrease in wakefulness after sleep onset on actigraphy. Daytime activity increased in both groups; however, the temporal delay in peak activity was significant only in responders. Participants who used the weighted blankets had a significant decrease in depression and anxiety symptoms.

Practice implications

Insomnia with comorbid psychiatric disorders is a common disorder occurring in primary care and specialty clinics. An estimated 10% to 30% of adults experience insomnia at any given time.¹What's particularly concerning is that once insomnia occurs, it can last for years. These disorders have enormous individual costs in the form of lower quality of life, impaired daily function and personal expenses. The average cost of treating insomnia is between $200 and $1,200 per year, and employees with insomnia typically lose 11.3 work days per year. The societal cost of insomnia is estimated at $63.2 billion per year.²

The pharmaceutical management available for insomnia is far from ideal. Recent retrospective studies have shown an increased risk of Alzheimer's disease and other types of cognitive decline associated with long-term use of zolpidem, benzodiazepines, antipsychotics, and antidepressants.³There is also the problem of lack of effectiveness. In 2017, the American Academy of Sleep Medicine (a section of the American Medical Association) found that the evidence for the use of hypnotics is “weak.”⁴and went on to suggest in other publications that cognitive behavioral therapy for insomnia (CBT-I) should be the first-line treatment for insomnia and drugs should only be used when CBT-I has failed, or in conjunction with CBT-I in severe or acute cases. Unfortunately, the availability of CBT-I practitioners is not sufficient to treat the large number of people suffering from insomnia.

Behavioral and other treatments for insomnia and psychiatric disorders that have no side effects are ideal. In this study, 1 patient reported feeling more anxious when using the weighted blanket. In particular, no other side effects were reported.

Weighted blankets apply even pressure across the entire body using either metal chains or glass beads sewn between 2 layers of fabric. Public media generally recommends that they be 8% to 10% of the person's body weight or less. There are several proposed mechanisms of action for their effect on insomnia. First, they are believed to work similarly to massages by simulating touch. We know that people sleep better when they feel socially safe, and touch can be part of that. The deep pressure can stimulate the parasympathetic action of the nervous system while simultaneously downregulating sympathetic activation. Deep pressure also increases oxytocin. Oxytocin promotes relaxation, security and sleep.⁵

The big question is how universal is the improvement in sleep from using a weighted blanket? This is not yet known as only a few studies have been conducted so far. Several small studies have been conducted looking at the use of weighted blankets by certain populations. A study of children with autism showed that sleep did not improve. Children with attention deficit hyperactivity disorder had improvement in insomnia with the weighted blanket, and adults with chronic insomnia who were otherwise healthy improved. A recent review article covering 8 studies concluded that although there is evidence for the use of weighted blankets in the treatment of anxiety, the evidence for use for insomnia is insufficient.⁶

So the question for now is: Can we recommend it to a wide range of people, some of whom also have comorbid conditions of various kinds? There are other considerations here. For one thing, using a weighted blanket is a procedure with no reported or known side effects. However, it is well known that persistent insomnia contributes to many other health conditions - from high blood pressure to anxiety and depression. Insomnia also contributes to lower lifetime incomes and societal costs. The price of a weighted blanket is quite low, and it is a treatment that is well received by patients. Therefore, at this time, we can recommend the use of weighted blankets for patients with insomnia while keeping an eye on the emerging literature.