One of the things I want to do with this blog is to provide ideas of how to help people. There have been lots of times over the years where I ended up having an issue that I needed to work through. When I was diagnosed with autism, this offered a range of different ways to help with some of the issues I was having. However, which one should I try? How do I find out various ways that people use to help? The answer ultimately was the internet. However, a lot of the sources used on the internet didn’t give the whole picture – giving an opinion without much to support it other than anecdotes. While this in itself is sufficient for giving something a go, I felt that I would love to see more evidence for each of these things.
The problem is that autism has had a severe lack of research in the right places. People have spent more time researching the “why” and diagnosis, which while important, has lead to a lack of research into the “how can I help”.
However, that doesn’t mean that research hasn’t been done – you just need to dig a bit deep to find them.
Today, we are going to look at one of my favourite things, weighted blankets. We are going to go through a systematic approach to review the item, look at the reported benefits and the evidence that exists for it.
IMPORTANT NOTE: Just because something has poor evidence to it, that does not mean that it can’t help you. However, when approaching anything you need to assess the risks versus the chance of a benefit and make your own mind up about whether to try something.
Weighted Blankets
What are they?
A weighted blanket is pretty much self-explanatory. It is two pieces of material stitched together with another material inside of it that causes it to gain weight. Looking at mine, it contains a inner lining with segments that contain beads of some variety. They come in a range of sizes from lap-pads and weighted snakes (long tubes that you can put over your shoulders) to full sized blankets.
They can come in a range of colours and materials (dependent on your supplier) so can be adapted for sensory sensitivities and just general preference. They also come in different weights, which should be adapted for the individual using the blanket.
How does it work?
Weighted blankets aim to stimulate proprioception in people who are undersensitive to the sense.
Proprioception is an old sense that exists in a lot of organisms. It is the sense responsible for telling you where your body is in space and can be thought of as the ‘mechanical deep pressure sense’. If you have functioning proprioception then you can close your eyes and still know where all of your body is. From there you can move and still do tasks based proprioception telling you where you are related to what you know about everything else from before you closed your eyes.
Proprioception is something that people can over”look” because of vision. If your sight it functioning properly, and your vestibular function (originating from the ear – is associated with maintaining balance) is mostly alright, then you are able to maintain stability even if your proprioception is not working – you only need two of the three at any time to function well. However, for those people, if you close your eyes then you can end up falling over or having lots of problems maintaining your position – as you then can’t tell where you are in space (the basis for a clinical test called Romberg’s test). Having a constant feeling of being unsteady, of not being able to tell where your body is, can cause a lot of stress as you have to be more careful with how you move so that you don’t bump into things.
Weighted blankets try to counteract that. They provide extra weighting that can stimulate proprioception. Generally, a lot of people with poor sensory integration are undersensitive to proprioception. If you are undersensitive to proprioception, weighted blankets give you extra stimulation that will make your pressure sense wake up and notice where you are. Ideally, this then leads to people feeling a lot more relaxed, as their body knows where they are so can stop worrying about everything around them and ease off some of this alertness that can gather up.
What are the potential benefits from using a weighted blanket?
- Feeling more relaxed meaning that you can interact with everything around you a bit better
- Helping with sleep – it has been said to help with insomnia, and as sleep problems are common in autism this can be a helpful benefit
- Being more focussed during tasks (as you are less distracted by your lack of proprioception) – some people have reported benefits in engagement in classes
- Helping as a part of a sensory integration programme involving other techniques being used in tandem.
What are the potential risks of using a weighted blanket?
- If the blanket is too heavy – they are recommended to be less than 10% of the person’s body weight (mine is a little less than that being about 8%). If it is too heavy then this can cause discomfort and, if really heavy relative to the user, may mean that they cannot move the blanket away when they need to.
- Financial cost – The ones I get cost around £125, which is pretty pricey for just something to try out (but acceptable if they work for you – as you can use them long term and there is cleaning advice available with them to keep them fresh).
- From what I’ve found it makes it harder to rest without them at times (though this is all in retrospect so isn’t the most appropriate).
What does the evidence say?
The evidence is mixed. First off, there aren’t many studies into the use of weighted blankets for any condition, and then less specifically angled towards autism. Those that have been completed mainly focus on sleep, which isn’t the only positive outcome from weighted blankets. Also the studies are generally not of a high quality (apart from one), which makes it difficult to tell if they are really helpful. Overall, more research is required in order to see if there is a consistent benefit.
However, this research is difficult to do. The benefit of a weighted blanket in a lot of ways is subjective and so not great for quantitative research studies. In order to make a good study to look at it you need to find objective measurements for the effect of the weighted blanket. One study does this well. However, it focusses on sleep (using the measurements of sleep duration, sleep efficiency, number of night awakenings and time awake after sleep onset), which doesn’t give the whole picture. Other studies try to create measurements that look at measurements that could be attributed to a bunch of other factors (ex. One study uses photoplethsmography that can show you the blood volume changes in tissues, which can be influenced by breathing and hydration). Instead, some studies use questionnaires, which are ultimately subjective measures and so don’t achieve their job completely. In this way, the research should not be taken as absolute.
Is there evidence to support them?
There is some evidence to support them. A study by Gee, et al. Reported moderate improvement in measurements for sleep quality in a study with four participants (sleeping 1-3 extra hours a night) and more consistency in the sleep they did have. However, this didn’t lead to consistent improvements in morning mood. This study has four participants, so doesn’t hold much power, but does show some benefits from the use of the blankets.
A study by Ackerley, et al. showed improvements in objective and subjective measurements regarding sleep. It was a study in Sweden completed over 4 weeks for each participant with 31 patients (11 male, 20 female). However, none of these patients are reported to be autistic, so removes some of its relevance to the population we are looking at.
Is there evidence to not support them?
There is also evidence against them. One of the best quality studies in the area, by Gingas, et al. focussing on children with ASD showed no effect. This study, completed in England, involved 67 children and was completed as a randomised control study, where one group was given blankets filled with plastic beads (effectively adding no extra weight) and the other group was given the blanket filled with metal beads (adding a weight). This was used for 2 weeks then the groups switched to using the other type of blanket for 2 weeks. This is a good methodology for blinding the experiment. They did some objective measures using actigraphy to measure sleep. However, there were some problems with tolerance of this technique, which the study identified as a weakness. It showed no statistical significant difference between the two groups (though some people using the weighted blanket maintained a slightly longer sleep of around 20 minutes, which while not statistically significant could be significant to the person). While there were no measured benefits, the participants and their parents reported liking the blanket and feeling better about the use of it.
Reichow, et al. report no benefit between not wearing a vest, wearing a non-weighted and a weighted vest at engagement in activities (I couldn’t access the paper to verify this). A lot of other studies also show no benefit.
Overall, the evidence was a bit disappointing with few good studies, and those that were good showing no benefit in their measurements.
Conclusion
There is not enough evidence to support the use of weighted blankets at this time. The best study out of them showed no benefits by objective measures. However, subjectively people like it and can feel better with it. The studies possibly need to identify participants who have problems with proprioception in order to study it more in this cohort. However, this could be challenging. There have not been any new studies looking at weighted blanket use in autism for a few years now, which is unfortunate when trying to evaluate it.
Overall, it is an unfortunate picture where they seem to not have a recorded benefit in research so far. But this doesn’t rule out their use. More studies still need to be done that could show something different. In the meantime what we can say is that it has a chance of benefit if you find yourself struggling with this ‘deep pressure’ sense and has limited risks if you use a weight less than 10% of your body weight and are careful with its use with children.
References:
Ackerley, R. Badre, G. Olausson, H. (2015). Positive effects of a weight blanket on insomnia. Journal of sleep medicine and disorders. 2 (3). 1022-1029.
Chen, H. Yang, H. Chi, H. Chen, H. (2012). Physiological effects of deep touch pressure on anxiety alleviation: the weighted blanket approach. 33 (5). 463-470.
Denny, E. Folkes Jr, W. Ghattas, I. Kaufmann, H. Williams, H. Potvin, M. (2018). A systematic review of the efficacy of weighted vests and blankets on people with ASD or ADHD. Thomas Jefferson University. (Not peer reviewed).
Gringras, P. Green, D. Wright, B. Rush, C. Sparrowhawk, M. Pratt, K. Allgar, V. Hooke, N. Moore, D. Zaiwalla, Z. Wiggs, L. (2014). Weighted blankets and sleep in autistic children – a randomised controlled trial. Paediatrics. 134. 298-306.
Reichow, B. Barton, E. Sewell, J. Good, L. Wolery, M. (2009). Effects of weighted vests on the engagement of children with developmental delays and autism. 25 (1). 3-11.
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