This post has been peer reviewed by Robert, Ph.D.
Weighted Blankets and Anxiety Preface
The research talked about today is a secondary part of a study previously posted that looked at whether weighted blankets were safe. For those of you who didn’t read it – which you should! – Here’s a quick recap: The researchers recruited 30 people and used a 30-pound weighted blanket to test whether they were safe by measuring subjects’ vital signs – pulse, blood oxygen, etc. – both with and without a weighted blanket. There were no differences in these measures when patients were under the blanket, so that’s a good sign for safety.
The secondary question addressed within the study was “Do weighted blankets help anxiety?”
Summary of Weighted Blankets and Anxiety
- Researchers tested the effect of five minutes under a weighted blanket on anxiety, using both physiological measures and self-report measures.
- There were no differences in physiological measures.
- The weighted blanket did reduce self-reported anxiety.
- More research is needed to clarify these effects.
How to Measure Weighted Blankets and Anxiety
Two forms of measurement were used to collect data on weighted blankets and anxiety:
- they measured electrodermal activity, which just means how sweaty your hands are getting. You know how when you’re scared or nervous, your hands get sweaty? Sweatiness is an excellent way to measure anxiety, so this was a useful tool for them to use.
- They measured electrodermal activity by attaching little rings to the subjects’ fingers, as shown in this figure. The rings measure skin conductance – again, the more moisture from sweat, the more conductance you get – and those wires go off to the device that records in real-time.
- They used self-report scales, or surveys. One of the scales was incredibly simple: they just asked the subject how anxious they were on a zero to ten scale. The other method was a bit more complicated. They used a well-known scale known as the State-Trait Anxiety Inventory-10 (STAI-10), with the “10” indicating the number of items on the scale.
Let’s look at the scale in a bit more detail. Below, you can see four items from the survey. As you can see, each item is answered from one to four, and answers are added together to get a total anxiety score.
Do Weighted Blankets Help Anxiety in Everyone?
The population recruited to participate in this study is not inclusive of every idiosyncrasy found in people throughout the world, however, it provides us with a general sample of adults who are anxious.
The people recruited for the study were people who were potentially very anxious – they were in the hospital for mental health concerns. The Allen Cognitive Level Screen (ACL) assesses global cognitive functional ability (Allen, Earhart, & Blue, 1992). An ACL score of 4.8 or higher and the ability to understand and sign the informed consent document helped determine the cognitive ability to participate. Exclusion criteria also included having open wounds, moderate to severe physical injuries, illiteracy, and a positive pregnancy test upon admission.
Although 40 participants met inclusion criteria, only 30 participants completed all of the steps required for study completion. Of the 10 participants whose data were not used due to lack of completion, reasons for exclusion included: discharge prior to completion of all steps, anxiety related to the study procedures, and the loss of willingness to participate with no reasons provided.
How Were Data Collected?
First, complying with the rules of ethics, the experimenters explained the study and got the consent of the patients to participate. After that, importantly, participants were assigned to one of two groups.
One group had the blanket placed on them for five minutes and then, after that, spent five minutes without the blanket, filling out the survey after each five minute period.
The second group was the reverse: they went without the blanket for five minutes, and then later had the blanket on them.
This division into two groups is proper scientific technique and is essential. Suppose they hadn’t done this, and patients all got the blanket for five minutes, followed by five minutes without it. If they found that anxiety was lower in the second five minutes, the researchers wouldn’t know if this was an effect of the blanket, or only because more time had passed. Splitting up the groups into one set of people that get the blanket first and one that gets the blanket second – called counterbalancing – avoids this problem. A diagram of the study procedure is shown below in Figure 1.
Do Weighted Blankets Help Anxiety?
Remember that the crucial thing to look at is the differences between the measurements when the patients were being treated with the blanket versus not. In terms of the skin conductance, the researchers found that there were no statistically significant differences between the average values for skin conductance when the patient was under the blanket versus not.
Now, those are the averages. Does that mean that weighted blankets won’t ever have an effect? No. Remember that only 30 people participated in this study. With a small sample size being studied, this information really cannot be generalized.
From the data that we see here, we just don’t know. Of course, these results were obtained using a small sample size where it is harder to find statistically significant effects. It could be that with a larger sample – more people participating – they would have found an effect. Further, many results in psychology and medicine show variation across people. That is, sometimes what works for one person doesn’t work for another. Additional work will be needed to explore if there is an effect of weighted blankets and, if so if there are differences in terms of these effects for different people.
Finally, what about the second self-report scale, asking people how anxious they were? Well, in psychology, sometimes the simple measures are the best. What the researchers found– see Table 2 for details – is that people report their anxiety to be nearly a full point lower after having the weighted blanket on for five minutes compared to the control condition, no weighted blanket.
This difference was statistically significant. As we have discussed elsewhere, this means that while the difference between these groups could have been merely due to chance, the data that we see suggests that they were not. Instead, the difference is probably due to the effect of the weighted blanket.
Weighted Blanket and Anxiety Conclusions from our Authors
From these results, weighted blankets look promising. For this group of people, just five minutes under a weighted blanket reduced how anxious they said they were while having no harmful effects on their health.
As with every study, we have to be cautious in interpreting these results.
First, let’s think for a moment about the fact that the researchers only used weighted blankets. Could it be that any blanket would have had the same effect? Do we know that the extra 30 pounds were important in creating the effect? Would more or less weight have been better, or possibly worse?
Second, recall that the subjects in this study were people being admitted to a facility because they were experiencing an issue with their mental health. Now, the sample did consist of some men and some women, and people aged from 18 to 54, so a broad range. So that’s good. However, it could be that there is something different about this group of subjects compared to others. We don’t know that’s necessarily the case, but this is an issue every scientific study has. You have to use a sample because you can’t test every single person, so you have to be cautious about generalizing from the sample that you have to the broader population.
Thirdly, the blanket was used for merely five minutes. The researchers justified this short duration by citing previous works where changes were seen within that short time frame, however, there are also studies which show that more time with a weighted blanket is needed for some individuals to experience shifts, such as Inamura et al. (1990a, 1990b) who found little effectiveness with deep pressure stimulation durations occurring in brief bouts.
Finally, take caution, anxiety is not a one-size-fits-all concept. Don’t believe me? There’s a whole chapter dedicated to different anxiety disorders in the DSM-5. In addition, people with different types of anxiety may see different SC shifts when faced with the same stressor.
Without knowing the specifics of each participant, we cannot generalize that weighted blankets will help with all types of anxiety. Certainly, there were shifts in anxiety levels, but maybe the participant came in with situational anxiety and although the blanket may have helped, this gives us no indication of how it would help someone with generalized anxiety. Also, the five-minute exposure to the weighted blanket helped them in the moment, but there’s no evidence of long-term effects.
However, what this article DOES tell us, is that 5-minutes is enough to experience some form of change for some people per self-report (33% of the participants). Some people did notice a decrease in symptoms of anxiety in using the weighted blanket. If a person truly feels that a weighted blanket attenuates their anxiety symptoms, then they may be more eager to use it in times of stress, even if the physiological data disputes their anxiety alleviation. The saying goes “mind over matter” and if a person believes they are experiencing less stress, then the body may follow suit.
Champagne, T., Mullen, B., Dickson, D., & Krishnamurty, S. (2015). Evaluating the safety and effectiveness of the weighted blanket with adults during an inpatient mental health hospitalization. Occupational Therapy in Mental Health, 31(3), 211-233.
Inamura, K., Wiss, T., & Parham, D. (1990a). The effects of a hug machine usage on the behavioral organization of children with autism and autistic-like characteristics: Part 1. Sensory Integration Quarterly, 18, 1-5.
Inamura, K., Wiss, T., & Parham, D. (1990b). The effects of a hug machine usage on the behavioral organization of children with autism and autistic-like characteristics: Part 2. Sensory Integration Quarterly, 18, 1-5.
Kraus, K. (1987). The effects of deep pressure touch on anxiety. American Journal of Occupational Therapy, 41, 366-373.
Speilberger, C. D., Gorsuch, R. L., & Luchene, R. E. (1970). State-trait anxiety inventory. Palo Alto, CA. Consulting Psychology Press.
Meet Our Peer Reviewer
Robert holds a PhD in psychology as well as a Masters of Public Administration. His research focuses on human social behavior, especially cooperation, moral judgement, and political attitudes. During his career as a social scientist, he obtained the rank of full professor, writing over 100 peer-reviewed articles and book chapters. Google scholar shows that his work has been cited more than 10,000. He currently works as a freelance writer and consultant.