Autism. Arguably, autism is one of the top keywords searched when consumers look into weighted blankets. Many companies claim that their weighted blankets for autism can “cure autism” or “alleviates all symptoms.” These are hefty claims, and without outlining the research behind these claims, it can be difficult to trust these statements. Any caregiver who has worked with a child or adult with autism knows that there are dozens of treatment options. It can all be overwhelming for someone who recently acquired a child with autism. Weighted vests and weighted blankets for autism –two common forms of deep pressure stimulation—are yet another piece to this ever-so complicated puzzle that never seems to be solved.
I am a mental health therapist who works with children at the moment, and autism is a diagnosis I see often albeit, I work with kids who are higher functioning. Common treatment goals for which kids with autism present for include improving social skills and attenuating persistent emotional distress such as anxiety. I’ve worked with many parents who come to me with a loss of confidence, confusion, and defeat. I am not here to tell you that deep pressure therapy for autism is the solution to autism because that would make me a liar. I am here to provide information and hypotheses based on the scarce literature available on this topic, so that you, as the consumer, can make an informed decision.
Before diving into the literature on deep pressure and weighted blankets for autism, it would be helpful to start from the beginning. What is autism, and what treatments are available?
What is Autism?
Autism is complicated and sophisticated, which makes it near impossible to define it in a simple sentence. What we know comes from studying thousands of individuals who seem to have these common trends in malfunction. Even these trends can be misleading, though, as autism is a spectrum, sometimes referred to in aggregate as autism spectrum disorder or ASD. There are higher functioning individuals who go on to live independent lifestyles and need little adaptations to get their needs met, and then there are those who become nonverbal and are sentenced to a life with constant support and monitoring. Autism is a neurological disorder that ties together two opposing disciplines: mental health and physical health. Clinicians and physicians work together to develop tailored treatment plans for individuals, but this can be a challenge when there is an apparent divide between the two disciplines.
For a full understanding of what is required out of a human to receive an autism diagnosis, we turn to the Diagnostic and statistical manual of mental disorders 5th edition (DSM-5). The DSM-5 is the bible of mental disorders, and what clinicians and physicians refer to when trying to put a name to the observed symptoms.
Neuroanatomy of the brain with autism.
To understand ASD, we turn to the brain. Our brains can best be compared to a computer, with wires – neurons – connecting and enforcing all the capabilities of the brain. Really if you think about it, the brain is very impressive, it has the power to compute and command at the drop of a hat, and we do not give this powerful organ enough credit where credit is due. As with any powerful machinery, there can be malfunctions that can cause anomalies. ASD is like that: a neurodevelopmental disorder that can cause a range of malfunctions in the way people process social and sensory input. By decoding possible areas of the brain that are affected by autism, we can begin to fill gaps between how the brain responds to weight and how that can alleviate symptoms of autism. This presents a challenge because autism –as evidenced by the timeline below –is only recently gaining traction in the scientific literature. So, the information below is still in the preliminary stage of “factual,” meaning take this information with a grain of salt because neuroscience is an ever-evolving discipline.
Overall Brain Size/Volume
Treffert (n.d) reviewed the work of Courchesne et al. (2001). discussing changes in head size and brain growth rate pertaining to children with ASD. Before birth, a fetus later found to have autism will have a slower brain growth rate. Between one to two months old and six to fourteen months old, the child will have an excessive increase in head size. Children who meet the criteria for autism will very often (but not always) develop larger brains compared to their peers between ages 2 to 5, but by middle to late childhood, their brain growth has slowed and will be more in line with their peers. The severity of symptoms of autism correlates to the rate and duration of abnormal brain growth; if the autistic brain grows more rapidly for a more extended period, the individual will have a higher severity of symptoms. Though this information is theorized to correlate with an autism spectrum disorder, it is not absolute as the researchers noted that 6% of fetuses who exhibited slower brain growth rate (i.e. eventually autistic) did not develop the disorder as they progressed throughout life; and not all autistic children had abnormal fluctuations in brain size.
As shown above, the cerebral cortex makes up a large portion of the brain. It is responsible for thinking, communicating, and perceptual processing –It is the most highly developed part of the brain (Pam, 2018). As mentioned earlier, autism has a social deficit component embedded within its psychopathology. Thus it makes sense that an autism spectrum disorder would impact this area of the brain. More specifically, we see what may be going wrong in targeted areas of the cortices of people who have autism, in particular, the following:
Fusiform face area (FFA)
The fusiform face area (FFA) is located in the fusiform gyrus of the inferior temporal cortex and is largely responsible for face recognition (Goebel, Muckli, and Kim, 2012). In a typical brain, fMRI can easily spot this area, as it lights up upon facial recognition. However, for people with autism, that activation is weaker (Deweerdt, 2015). There is an agreement amongst the scientific community that there is a link between social deficits and facial recognition (Golarai, Grill-Spector, & Reiss, 2006), and as we know, people with autism have social deficits. (NIH, 2019)
Anterior cingulate cortex (ACC)
Balsters et al. (2017) found a link between the anterior cingulate cortex (ACC) –an area of the brain associated with reward prediction error (and implicated by Lockwood et al, 2015, in social processing for those having trait empathy)– and social prediction error in people who are autistic. They found unusual activity within the ACC during a game that involved understanding the decisions of other players; there was weak ACC activity in ASD patients v strong in control subjects. The researchers have identified this information to mean that the normal response in the ACC –checking what is expected to happen vs what happens (in this case, in a social situation)– is somehow going wrong in ASD. This might mean, for example, that ASD patients are setting up poor or no expectations and/or that social input is not correctly registering after expectations have been set, among other possibilities. As usual, they call for further research to discover more specifics.
The corpus callosum is the part of the brain that connects the two halves of the cortex, allowing them to communicate and allowing coordination between them to function seamlessly for us. For a large portion of people who have autism, they are missing either part or all of their corpus callosum (Deweerdt, 2013). Those with partial corpus callosum will have the ability to understand the straightforward language but misidentify secondary meanings such as sarcasm or nuances. There is a hypothetical correlation between the degree of loss and symptom severity, wherein those who are missing their corpus callosum in its entirety may have more severe symptoms (often appearing similar to or consistent with autism), while those with partial remnants are expected to live a more self-sufficient lifestyle having only minor social deficits. Another issue associated with a lack of corpus callosum is inattention; thus, the underdeveloped or nonexistent corpus callosum is linked to ADHD as well, which shares some features with autism (Griswold, 2016; Baribeau & Anagnostou, 2015).
The limbic system –or the areas of the brain implicated in processing emotions –includes the hippocampus and the amygdala (“The Limbic System,” 2019). On average, although autistic individuals had larger amygdalae (especially on the right side of the brain) by age 2 and still at age 4, those with social attention deficits had a smaller amygdala than those without, which might imply that some compensatory process is kicking in after the amygdala gets so large to force it to become reduced in volume (Mosconi et al., 2009). In previous literature –when an amygdala has been removed –they have found that their sympathetic nervous system is less easily triggered (aka fight or flight) and there is eye contact avoidance. (Adolphs, Gosselin, Buchanan, Tranel, Schyns, & Damasio, 2005; Choi, & Kim, 2010). This information can help explain why aggression is a common symptom in people who have autism (“Brain Differences and Autism: An overview of the structural differences in the autistic brain,” n.d.). The hippocampus is the part of the brain heavily involved in associating contextual information with memory and is commonly thought to work with the amygdala to allow appropriate fear responses (Chaaya, Battle, & Johnson, 2018); its reduced size in people with autism may also help explain their sensory defensiveness (Green, & Ben-Sasson, 2010; “Brain Differences and Autism: An overview of the structural differences in the autistic brain,” n.d.).
Tang et al. (2014) have found that children who are diagnosed with autism have more synapses (where messages are transmitted from one neuron and the next, which involves specialized structures to send –usually axons– and receive – usually dendrites and their spines– the information) compared to those without the diagnosis. Children naturally have more synapses compared to adults, but as we age these synapses are pruned away; however, the brains of autistic children do not pare off the synapses nearly as much, and thus they may be, in a very neuroscientific sense, “overstimulated” for the duration of their life.
There is no cure for autism, and one will endure symptomology for the duration of their life; however, the treatments are ever-evolving to provide relief from symptoms that inhibit autonomy. Treatment for autism can best be broken down into two categories: evidenced-based and non-evidenced based. The delineation between these two treatments comes from the research. If a treatment’s efficacy is displayed through various studies and tests, then it is evidence-based; A neighbor who recommends coloring as a treatment for autism is recommending a non-evidenced based treatment, as there is no scientific literature to support the claim that coloring is an effective intervention for symptom management. If you are well-versed in the jargon surrounding autism then treatments such as ABA, CBT, speech therapy, occupational therapy, sensory integration therapy, and the picture exchange communication system will ring a bell of familiarity. These are all evidence-based treatments that are tried and true to mitigating symptoms of autism. Getting a child into services in early childhood is better for treatment success.
Complementary and Alternative treatments are a more holistic approach, and therefore there is little literature. Special diets, essential oils, and heavy blankets for autism fit into this category. Deep pressure is gaining traction in the scientific community, though, and has the potential to gain merit as an evidenced-based intervention. Below we highlight some of the key research which explores weighted interventions effects on specific symptoms of autism. While not comprehensive, these data do give us insight into the effectiveness and limits of weighted interventions as mitigation for symptoms of autism.
Autism Treatment Timeline
If you are anything like me, this timeline has shocked you. We did not have modern autism treatment 30 years ago. Moreover, up until then, electrical shock therapy was used! Luckily, we have strayed from those ineffective and harmful treatments to something more practical, but this timeline shows us that autism treatment is still new and changing. Every year a new intervention shakes the field and questions our previous understandings of the disorder. Another pertinent take away from this timeline occurred in the 1970s with Temple Grandin –the developer of the Hug Machine. Her development of this machine paved the way for deep pressure stimulation and its place in autism treatment – We will focus on this.
Temple Grandin is a famous animal science researcher who was diagnosed with autism at the age of two. At that time, the normal treatment course was institutionalizing children who met the criteria for autism, but Temple Grandin’s mother fought against that treatment and instead utilized speech therapy and intensive therapy.
Fast forward to decades. Temple was on her aunt’s farm and observed cattle as they went through a “shoot” where pressure was applied around their body and noticed that after the stimuli of the shoot, the cattle appeared calmer. As she observed this, she wondered if there would be a similar connection between pressure and humans. Mainly, she wanted symptom relief for herself. Temple created what is now referred to as the Hug Machine [Squeeze Machine], which is a large contraption that provides even pressure around the user’s body. She researched the effectiveness of this Hug Machine with various populations and varying applications (i.e. persistent pressure versus pulsating pressure). Her research confirmed that her Hug Machine did provide an alleviation from arousal symptoms experienced by those who experience anxiety, and those who struggle with autism. Further, she found that prolonged use enabled users to experience symptom management longer post-use. Essentially, the additional weight against the body helps balance our autonomic nervous system –responsible for the flight or fight response –and keep our heart rate low despite anxious thoughts.
Temple Grandin’s patented Hug Machine was the first use of deep pressure stimulation as a treatment for anxiety and sensory defensiveness symptoms. Deep pressure stimulation or deep touch pressure is/are the terms used to define interventions that provide pressure against the skin (e.i weighted blankets or weighted vests). From Temple Grandin’s Hug Machine, occupational therapists implemented this intervention into their treatment in the form of “mat sandwiches” and weighted vests. Therefore, a lot of the literature surrounding deep pressure stimulation and autism utilizes weighted vests, as these preceded weighted blankets.
Research on Autism and DPS
As you can see from the timeline, modern autism treatment is fairly novel, therefore the research surrounding particular interventions such as deep pressure stimulation is a bit scarce in relation to the research of other treatment interventions for other conditions. Despite the lack of abundant literature, there are still data that can help us begin to close the gaps between deep pressure stimulation as a treatment intervention for autism.
There are seven studies that hold merit in this discussion, and each will be explored and compared to draw conclusions on what is known about deep pressure stimulation interventions for autism.
Study 1: The effects of weighted vests on the engagement of children with developmental delays and autism.
For this experiment, three children with an autism diagnosis and around the age of four were recruited to determine if weighted vests would improve engagement. We know from above that typical symptoms expressed in children with autism include lack of social engagement and hyper-focus on particular activities or objects. With autism, education can be difficult due to the extra challenge of motivating and maintaining engagement.
The goal of this study was to determine if weighted vests can act as an intervention to improve engagement for this symptom. The weighted vests weighed about 5% of the child’s weight and were worn in ten-minute increments. Unfortunately, these results did not yield any benefit in relation to the weighted vests, as there were insignificant changes between the time where the vest was used and when the vest was not used. Click here to read our full article on this study.
Study 2: The effects of weighted vests on appropriate in-seat behavior of elementary-age students with autism and severe to profound intellectual disabilities (Experiments 1 and 2).
This study was a two-parter with three participants between the ages of five and nine who had varying severities of autism. When boiled down, this study essentially looked at appropriate classroom behavior –If the child could stay in their seat and complete an activity while wearing a weighted vest weighed 5% of the child’s body weight, and weight was evenly distributed. Data were collected during the first 10 minutes of the activity out of 30 minutes, and data were analyzed via observation.
There are a couple of issues with this study, which I must point out as someone who intends on being an objective scientist.
- Let’s look at the age group – 5-9-year-olds. How many typical 5-9-year-olds do you know who can focus for 30 minutes? Better yet, how many adults do you know that can truly fixate on a task for a solid 30 minutes? When I sit down to work I often need to get my environment just right to “enhance the focus,” make sure I’m equipped with caffeine and water and then check my emails a few (dozen) times before settling into a focused state. Yes, the research has shown that there are brain abnormalities which restrict the focusing abilities of children who have autism, but how can focus accurately be measured?
- The standard weight for weighted vests is 10% of one’s body weight, so I wonder what led to the researchers reducing this percentage. Could this be the confound that inhibited the focusing abilities of these children?
- Finally, we do not know what was occurring in these children’s lives. We do not know if a holiday was approaching, thus reducing focus even more, or if something was going on in their lives. I know that this could be true for any study, but the statement still rings true here.
While still similar in nature to the studies aforementioned in the sense of testing a form of attention [focus], this study changes the tune by studying toddlers and involving their mothers into the equation. Four males between the ages of 27 months to 33 months, and who had autism, wore weighted vests that were 5% of their body weight while engaging in play with their mother. Social engagement is defined as participation in a social setting. So, in this study, social engagement would be defined as the toddlers apparent interactions (eye contact, pointing, or motioning) with mother. An assessment entitled “The Parenting Moral Index” was also distributed to mothers involved, to gain information on their perceptions when the weighted vest was utilized in this study. Unfortunately, like the other studies, there were no significant changes when the weighted vest was used, however, the mother’s morale score increased with weighted vest use. What does this mean? It means they felt better knowing they were trying interventions to ameliorate symptoms, essentially. Click here to read our entire analysis of this study.
Study 4: Calming effects of deep touch pressure in patients with autistic disorder, college students, and animals.
This study, arguably the most popular within the deep pressure stimulation industry, found that deep pressure stimulation was effective in reducing symptoms associated with autism. This is the study that you have most likely come across when researching weighted blankets an autism, and if not, I’m here to update you. As aforementioned previously in this article, the deep pressure industry was essentially founded by Temple Grandin who applied techniques used with cattle to humans, and found success. This is the study which demonstrated the success in that. This is also the only study available (that I could find) which utilized adults as participants.
Okay, enough preface, here’s the breakdown. Dr. Grandin recruited 25 college students and 9 children to test her Hug machine (also known as squeeze machine). This machine is unique in the sense that the mechanism allowed users to apply their desired pressure rather than having a specific amount preassigned based on body weight. Also, as opposed to weighted vests, this machine provided pressure all around the body, and not just on a particular portion. You can now see why this study has been the main argument for weighted blankets, which also apply pressure all around the body (and a cocooning effect but more on that later). Subjectively and objectively the data of her research showed promising results for deep pressure stimulation as an intervention for anxiety. We have written more about this study here.
Previous studies we’ve highlighted have fixated on the variable of attention (or focus). However, anxiety can cause lack of focus, no? People with autism experience anxiety over sensory overload, change in routine, and at times social interaction. If anxiety is the underlying
component of all of these symptoms, then mitigating anxiety would be a reasonable step in treatment. This leads me to another completely off topic rant on how health systems tend to patch symptoms rather than figure out and fix underlying conditions, but I digress.
Study 5 and 6 (case studies): The effects of deep pressure on self-stimulating behaviors in a child with autism and other disabilities & The effects of sensory stimulatory treatment on an autistic child.
Case studies are different in the sense that they follow only one person and gather lots of detailed information on this one person to make a case as to why this treatment may be effective for others. Needless to say, they wouldn’t go through all the effort of publishing research with a case which did not respond to the intervention at hand (or they rarely do so, and only to prove a point). Therefore, the two case studies I will highlight were a success in the sense of deep pressure stimulation and autism; the full article review can be found here. Both used deep pressure stimulation tactics on the participants’ arms –something to consider as you read
The first case was a young, eight year old, girl who was in a state of distress in school and in occupational therapy. Her treatment team noticed that she self-stimulated by banging her arms against the table. Her occupational therapist constructed arm compression wraps and observed the changes in the behaviors. There was a significant reduction in distress and self-harming stimulation.
The second case was a young boy with severe autism who self injured by punching himself, to the point where surgery was needed. He was admitted into an inpatient facility where his treatment team constructed compression arm wraps and noticed that the self-injurious behavior almost immediately subsided.
With these two studies and the prior discussed, we can deduce that something about pressure all around, and more specifically in the arms alleviates some symptoms.
Study 7: Brief report: Autistic children’s attentiveness and responsivity improve after touch therapy.
Another successful study that highlights the potential for deep pressure stimulation as an intervention for autism. Occupational therapists provided what can best be described as a deep tissue massage to 11 children, twice a week, for 15 minutes. Then observations and questionnaires were used to determine if the touch therapy was helpful in improving attention in children with autism. The results showed that off-task behavior significantly decreased, attention to irrelevant sounds, and stereotypical behaviors decreased in the group of children who experienced touch therapy. Now I must caveat that there is a theory that the children improved due to learned helplessness, meaning because they had no control over the touch therapy their body just accepted it, rather than resist due to the pointlessness of resisting. Due to lack of follow up and repetition of this study, there is no way to determine if the learned helplessness explains the response, or if the touch therapy did indeed provide benefits.
Study 8: Weighted blanket and sleep in autistic children – A randomized controlled trial.
And then we come to the final study which will be discussed in this article -the only study that actually touches on weighted blankets as an intervention. For this study, 67 children between the ages of 5 and 16 who met the criteria for autism with sleep disturbances were studied with and without the use of a weighted blanket. Although parents self-reported liking the weighted blanket, there was no significant difference in sleep for the children during its use. Another bust or deep pressure stimulation, but why?
Themes of Research: What can we Conclude about Weighted Blankets for Autism?
Notice any themes amongst all the studies we’ve presented? It appears as though inattention associated with autism is overall not improved by weighted vests. In fact, in all these studies which used weighted vests, there were no significant changes. This isn’t to say that weighted vests are ineffective all around, but rather just in these circumstances. Possibilities for why this is the case are not enough weight, inattention associated with autism just not being a symptom which can be ameliorated by weighted vests, or flawed research design.
It is interesting that we don’t see an improvement in attention within deep pressure stimulation and autism research, because in our ADHD article, we discussed how we theorized weighted blankets could improve attention and other ADHD-related symptoms based on deep pressure stimulation and ADHD research. While these two disorders are different (obviously) they do have similarities in that there is a sensory processing problem and inattention. My best defense for this disparity is how each set of symptoms is initiated within the brain, and how weighted blankets interact with those portions of the brain. For example, in our ADHD article we state that weighted blankets allow people to organize stimuli in their environment better which allows them to focus. The research highlighted above has primarily used weighted vests, and a weighted vest could provide sensory concerns which prevent an improvement in attention. I would be curious to see if a study that uses weighted blankets instead of weighted vests for inattention in autism would yield a different result.
However, as shown above, there are some examples of instances where deep pressure stimulation has been effective in attenuating symptoms caused by autism. Why is that? It appears as though there are two factors which ring true when treating autism with deep pressure stimulation: (1) there may be a cocooning effect which when combined with pressure elicits therapeutic benefits. Case in point, Temple Grandin’s Hug Machine research. (2) Pressure needs to be applied to certain areas, depending on the symptom being exhibited and the severity. For example, the case studies both showed symptom reduction when arm compression wraps were implemented.
The collection of these studies help us come closer to identifying the limits and confounds of deep pressure stimulation as a treatment option for autism. With many different dosing options and varieties of pressure applications, it can be overwhelming for someone to pick a starting point. From these data, it appears as though the swaddle is a feature which is helpful in deep pressure stimulation mechanisms to attenuate symptoms of autism, in which case people choosing to use these interventions should seek out options which provide pressure around the body. The frequency and duration of this intervention is still up for discussion as there have been various dosing protocols in literature and it is difficult to say with certainty which would be appropriate as a general guideline; hopefully, further research will make this more clear.
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