People With Autism Experience Pain at a Higher Intensity

Summary: People with autism experience pain at a higher intensity than those not on the autism spectrum and are less adaptable to the sensation. This revelation contradicts the prevailing belief that those with ASD tend to be indifferent to pain.

Source: Tel Aviv University

A new study has examined the pain perception among people with autism and found that they experience pain at a higher intensity than the general population and are less adaptable to the sensation.

This finding is contrary to the prevalent belief that people with autism are supposedly ‘indifferent to pain’.

The researchers expressed the hope that the findings of their study will lead to more appropriate treatment on the part of medical staff, caregivers, and parents toward people with autism, who do not always express the experience of pain in the usual way.

The study was funded by the Israel Science Foundation, and was led by four researchers: Dr. Tami Bar-Shalita of the Sackler Faculty of Medicine at Tel Aviv University who initiated the study, in collaboration with Dr. Yelena Granovsky of the Technion and Rambam Medical Center, and Prof. Irit Weissman-Fogel and Prof. Eynat Gal of the University of Haifa. This study constitutes a framework for the theses of PhD students Tzeela Hofmann and Mary Klingel-Levy, and three articles based on it have already been published or approved for publishing.

The present study has been published in the prestigious PAIN journal.

Dr. Bar-Shalita explains: “approximately 10% of the general population suffer from sensory modulation dysfunction, which means sensory hypersensitivity at a level that compromises normal daily functioning and quality of life.

“These people have difficulty, for example, ignoring or adapting to buzzing or flickering of fluorescent lights, humming of air conditioners or fans, or the crunching of popcorn by someone sitting next to them in the cinema. In previous studies in the lab we found that these people suffer from pain more than those without sensory modulation dysfunction.

“Since it is known that sensory modulation dysfunction occurs in people with autism at a rate of 70-90%, it constitutes a criterion for diagnosing autism, and is associated with its severity. We were interested in exploring pain perception in autism, so we asked: do people with autism hurt more than the general population? This question was hardly studied in the lab before we got started.”

According to the researchers, for many years the prevalent opinion was that ‘people with autism hurt less’ or that they were ‘indifferent to pain’. Actually, ‘indifference to pain’ is one of the characteristics presented in the current diagnostic criteria of autism. The proof of this was, supposedly, their tendency to inflict pain on themselves by self-harm.

Dr. Bar-Shalita: “this assumption is not necessarily true. We know that self-harm could stem from attempts to suppress pain, and it could be that they hurt themselves in order to activate, unconsciously, a physical mechanism of ‘pain inhibits pain’.”

This study is a laboratory pain study approved by the ethics committee of the academic institutions and Rambam Medical Center. The study included 52 adults with high-functioning autism (HFA) and normal intelligence – hitherto the largest reported sample in the world in studies on pain among people with autism.

The study made use of psychophysical tests to evaluate pain, commonly used in the area of pain study. These methods examine the link between stimulus and response, while the researcher, using a computer, controls the duration and intensity of stimulus and the examinee is asked to rank the intensity of the pain felt by him on a scale of 0 to 100.

The findings have proven beyond doubt that people with autism hurt more. Furthermore, their pain suppression mechanism is less effective.

The researchers: “we conducted a variety of measurements, aimed among other things at examining whether the hypersensitivity to pain derives from a sensitized nervous system or from suppression of mechanisms that are supposed to enable adjustment and, over time, reduce the response to the stimulus.

“We found that in the case of people with autism, it is a combination of the two: an increase of the pain signal along with a less effective pain inhibition mechanism.”

This shows a child crying after falling over
Actually, ‘indifference to pain’ is one of the characteristics presented in the current diagnostic criteria of autism. Image is in the public domain

Dr. Bar-Shalita concludes: “Our study constituted a comprehensive, in-depth study of the intensity of pain experienced by people with autism. The prevalent belief was that they are supposedly ‘indifferent to pain’, and there are reports that medical and other professional staff treated them accordingly.

“The results of our study indicate that in most cases, the sensitivity to pain of people with autism is actually higher than that of most of the population, while at the same time they are unsuccessful at effectively suppressing painful stimuli.

” We hope that our findings will benefit the professionals and practitioners handling this population and contribute to the advancement of personalized treatment.”

In additional articles soon to be published, the researchers have examined the brain activity of people with autism during pain stimuli, and sub-groups within this population concerning their perception of pain.

About this ASD and pain research news

Author: Press Office
Source: Tel Aviv University
Contact: Press Office – Tel Aviv University
Image: The image is in the public domain

Original Research: Closed access.
Indifference or hypersensitivity? Solving the riddle of the pain profile in individuals with autism” by Tami Bar-Shalita et al. PAIN


Abstract

Indifference or hypersensitivity? Solving the riddle of the pain profile in individuals with autism

Excitatory–inhibitory (E/I) imbalance is a mechanism that underlies autism spectrum disorder, but it is not systematically tested for pain processing. We hypothesized that the pain modulation profile (PMP) in autistic individuals is characterized by less efficient inhibitory processes together with a facilitative state, indicative of a pronociceptive PMP.

Fifty-two adults diagnosed with autism and 52 healthy subjects, age matched and sex matched, underwent quantitative sensory testing to assess the function of the (1) pain facilitatory responses to phasic, repetitive, and tonic heat pain stimuli and (2) pain inhibitory processes of habituation and conditioned pain modulation. Anxiety, pain catastrophizing, sensory, and pain sensitivity were self-reported.

The autistic group reported significantly higher pain ratings of suprathreshold single (P = 0.001), repetitive (46°C- P = 0.018; 49°C- P = 0.003; 52°C- P < 0.001), and tonic (P = 0.013) heat stimuli that were cross correlated (r = 0.48-0.83; P < 0.001) and associated with sensitivity to daily life pain situations (r = 0.39-0.45; P < 0.005) but not with psychological distress levels.

Hypersensitivity to experimental pain was attributed to greater autism severity and sensory hypersensitivity to daily stimuli.

Subjects with autism efficiently inhibited phasic but not tonic heat stimuli during conditioned pain modulation.

In conclusion, in line with the E/I imbalance mechanism, autism is associated with a pronociceptive PMP expressed by hypersensitivity to daily stimuli and experimental pain and less-efficient inhibition of tonic pain. The latter is an experimental pain model resembling clinical pain.

These results challenge the widely held belief that individuals with autism are indifferent to pain and should raise caregivers’ awareness of pain sensitivity in autism.

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  1. My son, who is nearly 30 years old, has Asperger’s. From the time he was a toddler, we worked on his sensory perception. I knew back then that his feelings (emotional and physical) are felt very intensely with no real way to express his intensity. It 8s remarkable to me that nearly 30 years later that I find an article supporting the most obvious of the challenges Asperger’s people deal with on a daily basis. I am disheartened that Science is just now making this connection.

  2. It’s a spectrum. Each person is different. Some feel pain less than normal, some more than normal, and some are sensory indifferent. And those 3 apply to multiple areas. For me, social and emotional pain are much more severe, and physical pain is maybe less. But because mental pain is so much worse by nature, physical pain becomes less by nurture. Running more, longer, faster, and harder, is therapy to cope with the mental pain. I miss being able to run 70+ mile weeks, I wore out my legs from so much “therapy”. But at 42, I can still almost run 12 miles under 7 minute pace. It’s much easier than coping with harsh mean people.

  3. Given a lot of us with Autism struggle with sensory overload, this should not come as a surprise and I never even knew about the notion that we Autistics are “indifferent” to pain.

    Well, that is bogus. I feel pain physically and mentally. My friends who are Autistic also feel pain, some more than me.

    And we all have different ways if dealing with it. For me, it is a lot of pain from stress related to work and socialising, so a lot of my time off is spent alone.

    Some think we are also indifferent emotionally. We are not. A lot of us are actually deeply emotional, but still struggle with recognising the emotions and expressing those emotions in an healthy way that does not end up in a meltdown.

    For instance, I am very blind to my own emotions and let it bottle up until I suddenly explode in a meltdown. Surprising myself and those around me. Thankfully, this does not happen often.

    When it comes to the social game, it varies. Some struggle a lot while others are social butterflies. I am able to pass as neurotypical, yet I still struggle a lot with social cues and keep small talk going. I find interacting with other Autists a lot easier because… Well we are all mostly in the same boat. And in a way, it feels like we are born with our own set of social cues. It makes me feel a bit like an alien.

  4. I’m not comfortable with some of the terminology used in this article, but the news of this research is brilliant and very exciting. This study could change so many people’s lives by helping us to convince clinicians and funding assessors of our reality and our needs. Hopefully it will validate all the people who fail to get benefits or the treatment they need, or who get discharged from pain clinics for being assumed to be faking symptoms. Autistics are nine times more likely to take our own lives, but this research, if properly understood by professionals, could significantly reduce that risk.

  5. My 7 year old grandson is autistic and without any doubt experiences pain at a much deeper level and for longer.As a family if he hurts himself we support him through this.It would never occur to us to see him as a wimp or to tell him not to be upset.Reading the latest research confirms our own observations. Thankyou.

  6. My entire life I’ve been called dramatic, wimpy and attention-seeking due to my adverse and perceived inability to handle stimuli that “neurotypical” can easily manage.

    I am “not autistic enough” to be taken seriously when it comes to needs that are different than neurotypicals, even by scientifically-educated loved ones, on a daily basis, even though I have been able to see I can’t handle what they can.

    Work, such as this, validates my needs, and what makes me different. Having peer reviewed sources allows me to take this to loved ones, who literally say I’m “weak” on a daily basis, and say “no. No I’m not. There is SCIENCE that explains, empirically, that I experience pain differently and more acutely than you. Stop.”

    I already knew that we experienced pain more acutely than neurotypicals, just by conversing with other ASD people on their experiences… but I’m SO glad that FINALLY we’re getting more and more studies showing that we ARE neurologically different, and that autism isn’t necessarily an intellectual disability, but a range of different neurological symptoms that make us unique as a group.

    Thank you, doctors.
    This isn’t just a scientific accomplishment. It’s truly helpful.

  7. Speaking as a “high functioning” autistic, I can say that my personal issue is that I have gotten so good at what is known as “masking” that I often mask my reaction to pain along with all of my other reactions to stimuli. This has led to medical professionals assessing me to be in “no apparent disress” many times. I simply refuse to be a whiner but I can assure that the pain is there if one takes my word for it.

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