Jul 28, 2021

Deep Pressure Therapy: Deconstructed

Deep pressure therapy is becoming popular as we learn more about weighted blankets, but how does the pressure make us feel good?

Your guide to understanding the science behind the Deep Pressure Stimulation

Have you ever wondered why new parents swear by wrapping their fussy babies up like burritos or why your friend puts a tight vest on their frightened dog on the 4th of July? Why a massage makes you feel SO darn good? Maybe you’re recently curious about how weighted blankets work. Good news- I’m here to fill you in on deep pressure therapy!

The science behind these practices is rooted in a mechanism called deep pressure stimulation (DPS) or Deep Touch Pressure (DTP).  To put it simply, we are talking about methods that can be used to simulate the physical and emotional sensations you’d get from a firm, loving bear hug and the “how and why” it can be so soothing.

What is Deep Pressure Therapy?

To understand what deep pressure stimulation is, we need first to understand a bit more about how the body senses touch.

The human body uses elaborate sensory systems to detect a variety of stimuli- like the light emitted from your computer screen right now or the sound of your music playing in the background, for example.  These sensory systems are activated by strategically placed nerve endings (often called receptors). When sensory receptors are stimulated, nerve impulses travel along nerve fibers to the brain, where sensory information is interpreted.

There are many types and subtypes of sensory receptors. For example, chemicals in your food stimulate different taste receptors on your tongue and give rise to familiar taste sensations such as salty, sweet, or sour- to name a few.  Photoreceptors in the retina of your eye are stimulated by different wavelengths of light, giving rise to the different colors that you see. Thermoreceptors allow you to sense hot or cold, and on it goes. There are five basic sensory systems in the body (sight, smell, taste, sound, and touch) and a few other integrated sensory systems that allow more complex sensory processing (like the vestibular and proprioceptive systems, that enable you to sense the positions of your body parts in space).

Your skin hosts several subtypes of sensory receptors (also known as mechanoreceptors) that allow you to detect different kinds of touch stimuli. These different nerve endings are specially packaged, positioned, and layered from superficial to deep so that you can discern light touch from vibration from deep pressure quite accurately.  You can even sense the individual hairs standing on end when you get the goosebumps!

Sensory Receptors In The Skin

skin receptors triggered by deep pressure therapy
Deep pressure stimulation refers to the activation of the touch sensory system, by applying a firm but gentle pressure, in a way that promotes the feeling of well-being in the body.

Aside from serving as a tactile sensory system, touch information can feed into more complex sensory processing pathways in the brain. For example, certain kinds of touch stimulate unique touch receptors that input to a part of the brain involved in processing emotions and can trigger positive feelings associated with a touch that are important for human connection. You get a different feeling when you’re cuddling your special someone than you do when your fingertips are typing away on a keyboard, you know? Your brain can do some complex things when it comes to associating sensations- like how certain smells can trigger strong emotions or memories (cool ha?).

What are the effects of Deep Pressure Therapy?

Swaddling, massage, pressure vests and weighted blankets are just some of the commonly used therapeutic tools available for deep pressure stimulation.  Before we can understand the effects of deep pressure stimulation, we need to understand what the body does with sensory information- because merely having the awareness that you’re being touched is not always the end of the story.

Sometimes sensory information elicits a rapid and reflexive response in the body. Think of how quickly you might spit out something that tasted awfully bitter or how fast you’d jump out of bed in the middle of the night if you felt a critter crawling on your leg. But not all stimuli give rise to conscious sensations. For example, sensory receptors in the walls of your blood vessels constantly monitor your blood pressure as a reflection of how stretched the vessels are.  These receptors can sense a rapid drop in blood pressure and reflexively trigger an increase in your heart rate to maintain sufficient blood flow through the body (so you don’t pass out when you stand up fast). Amazingly, your body is endlessly using sensory information to get an idea of what’s going on in the environment (internal and external), so that it can respond in a way to protect you! You should probably thank your body.

These automatic, reflexive responses are mediated by both the nervous system and the endocrine system (think hormones).  The autonomic division of the nervous system, in particular, includes two subdivisions that are dynamically influencing the “mode” your body is working in at all times. While you may be familiar with these two modes as “flight or fight” and “rest and digest,” they are technically called sympathetic and parasympathetic subdivisions of the autonomic nervous system, respectively.  The activity of these two subdivisions is, in a way, analogous to the gas and brake pedals in a car- you need to use them both in a coordinated way to drive properly at all times. If you’re running a yellow light, you press the gas and let up on the brake.  The same goes for the sympathetic and parasympathetic systems- they are both working reciprocally so that your body functions properly and responds appropriately to different situations.

Let’s say you’re running from a bear, for example. Your sympathetic nervous system will predominate, and your heart rate and blood pressure increases, and blood is diverted away from the digestive tract and toward the muscles, in your legs, so you can run fast (because you’re not worrying about digesting that burger if you’re being chased by a bear)! On the other hand, if you’re getting a massage, the parasympathetic nervous system predominates, and your heart rate and blood pressure decrease, circulation improves throughout the body, and you’re feeling pretty good. That’s because, alongside parasympathetic activation, safe and comforting situations promote the release of feel-good neurotransmitters like serotonin and dopamine that promote a sense of well-being.

Naturally, during the body’s stress response, sympathetic activation predominates, and levels of the well-known stress hormones adrenaline and cortisol increase in the bloodstream.  Under the right circumstances, this is a helpful and protective response (think back to the bear situation). What your body perceives as a threat or dangerous situation can vary, and chronic stress is something many of us feel we live with. But certain conditions are associated with imbalance or over-activation of the stress response – like autism spectrum disorder, ADHD, and sensory processing disorder.  In these circumstances, the body’s stress response is more easily triggered, and often, the processing of sensory information is altered. This can lead to a variety of symptoms, including irritability and anxiety.

Deep pressure stimulation triggers a calming reflex in the body by activating the touch sensory system. It has been shown to reduce sympathetic activation and stimulate the parasympathetic nervous system! Studies also show that individuals report reduced anxiety when utilizing Deep Pressure Therapy. No wonder we like massages so much!

Autonomic Nervous System With Deep Pressure Therapy Explained

results from deep pressure stimulation

How is Deep Pressure Therapy used?

It all started with the “hug machine” (yup, it’s exactly what you think it is)- which was pioneered by Temple Grandin, who has autism spectrum disorder. Individuals with autism spectrum or sensory processing disorders often have altered touch sensitivities and overactive sympathetic responses, and sensory modulation techniques like the application of Deep Pressure Therapy has proven to be an effective therapy to reduce stress in such cases.

examples of deep pressure stimulation tools

There are many tools and methods available for Deep Pressure Therapy at this point, and the therapeutic use of Deep Pressure Therapy has been extended to conditions like ADHD and mental health disorders, including anxiety.  More recently, the use of Deep Pressure Therapy techniques in relieving symptoms of stress, and a variety of other conditions, is gaining popularity (although we could use a little more hard science).

Make sure you check out our Blog, where we aim to evaluate research findings in detail (broken-down, of course ☺).

Circle back to the weighted blanket…

Alright, so you’ve learned a good amount at this point about deep pressure stimulation, the effects it can have, and how it can be used therapeutically (don’t you feel informed?).

From the “hug machine” to pressure vests, and all the things in between, it’s probably clear that there are a lot of options available for using Deep Pressure Therapy as a tool.  Weighted blankets are one of them, and they are just what they sound like- blankets that have been purposefully filled with a heavy material that provides a significant and evenly distributed weight over an individual. Much thought has gone into the development of the weighted blanket, including choice of filler (the “weighting” material), distribution of the filler, comfort of the blanket, temperature regulation, size, and how much weight should be used.

Weighted Blankets are a very accessible and cost-effective option for distributing even pressure all over the body, and have been shown to reduce stress and anxiety.

Will Deep Pressure Therapy

and the weighted blanket “work” for me?

That’s a hard question to answer.  While there is data out there backing the therapeutic benefits of the weighted blanket, it is context-specific and somewhat limited- more data on the effects for other conditions would be great! Having said that, we all know there’s rarely ever a one-size-fits-all solution for coping with stress, but there are countless options available!  While that can be overwhelming, it means there are a lot of available tools to try. In the end, like most therapies, their value is most realized by the individual themselves- what works for one person may or may not work for another. You know the saying: you’ll never know unless you try it.

Plus, who doesn’t love the feeling of wrapping up warm and tight in a blanket?  The cool thing is, now you know why!

Want to learn more?

Abraira, V.E. & Ginty, D.D. (2013). The sensory neurons of touch. Neuron, 79(4), 618-39. DOI: 10.1016/j.neuron.2013.07.051.

Bestbier, L. & Williams, T.I. (2017). The Immediate Effects of Deep Pressure on Young People with Autism and Severe Intellectual Difficulties: Demonstrating Individual Differences. Occupational Therapy International, 2017, 1-7, DOI: 10.1155/2017/7534972

Chen, H.-Y., Yang, H., Chi, H.-J. & Chen, H.-M. (2013). Physiological Effects of Deep Touch Pressure on Anxiety Alleviation: The Weighted Blanket Approach. Journal of Medical and Biological Engineering, 33(5), 463-470. DOI: 10.5405/jmbe.1043.

Chen, H.Y., Yang, H., Meng, L.F., Chan, P.S., Yang, C.Y. & Chen, H.M. (2016). Effect of deep pressure input on parasympathetic system in patients with wisdom tooth surgery. Journal of the Formosan Medical Association, 115(10), 853-859. DOI: 10.1016/j.jfma.2016.07.008

Edelson, S.M., Edelson, M.G., Kerr, D.C. & Grandin, T. (1999). Behavioral and Physiological Effects of Deep Pressure on Children With Autism: A Pilot Study Evaluating the Efficacy of Grandin’s Hug Machine. American Journal of Occupational Therapy, 53(2), 145-152. DOI: 10.5014/ajot.53.2.145

Grandin, T. (1992). Calming Effects of Deep Touch Pressure in Patients with Autistic Disorder. Journal of Child and Adolescent Psychopharmacology, 2(1), 63-72. DOI: 10.1089/cap.1992.2.63

Krauss, K.E., (1987). The effects of deep pressure touch on anxiety. The American Journal of Occupational Therapy, 41(6), 366-73. DOI:10.5014/ajot.41.6.366

Lin, H. Y., Lee, P., Chang, W.D. & Hong, F.Y. (2014). Effects of weighted vests on attention, impulse control, and on-task behavior in children with attention deficit hyperactivity disorder. The American Journal of Occupational Therapy, 68(2), 149-158. DOI:10.5014/ajot.2014.009365

Marco, E.J., Hinkley, L.B., Hill, S.S. & Nagarajan, S.S. (2011). Sensory processing in autism: a review of neurophysiologic findings. Pediatric Research, 69(5 Pt 2), 48R-54R. DOI: 10.1203/PDR.0b013e3182130c54.

McGlone, F., Wessberg, J. & Olausson, H. (2014). Discriminative and affective touch: sensing and feeling. Neuron, 82(4), 737-55. DOI: 10.1016/j.neuron.2014.05.001.

Reynolds, S., Lane, S.J. & Mullen, B. (2015). Brief Report: Effects of deep pressure stimulation on physiological arousal. American Journal of Occupational Therapy, 69(3), 6903350010p1-5. DOI: 10.5014/ajot.2015.015560.

Schaaf, R.C., Benevides, T.W., Leiby, B.E. & Sendecki, J.A. (2015). Autonomic dysregulation during sensory stimulation in children with autism spectrum disorder. Journal of Autism and Developmental Disorders, 45(2), 461-72. DOI: 10.1007/s10803-013-1924-6.

Giulia Gurun

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