Many individuals in the autism spectrum have sensory abnormalities that can either numb or sensitize them. In a population study of 208 autistic children 20-54 month of age referred to a habilitation center for early intervention, parents reported a large prevalence of pain and hearing abnormalities (44% exhibited over-reactivity to sound while 40% exhibited under-reactivity to pain). Those diagnosed as typically autistic (nuclear autism with no learning disability) had the highest number of affected modalities. Those children classified as belonging to an “autistic features” subgroup had the lowest number of affected modalities (Klintwall et al., 2011). These sensory abnormalities manifest themselves early in childhood, thus offering some of the first signs of autism risk and a possible target for intervention.
Sensory abnormalities in autism may go unnoticed due to communication difficulties and/or a lack of understanding of what is going on in your body (interoceptive deficit). It may be hard for some autistic children to imagine that their suffering is different from what everyone else experience. Do they have to accept pain in the belief that everybody else does?
Indeed, describing the different domains of pain perception entails a complex thought process that requires the ability to ascribe mental states to oneself and others. Although Theory of Mind is affected in some autistic individuals, chronic pain itself may impair mentalizing and emotional awareness (Zunhammer et al., 2015).
How do you describe pain, e.g. jolting, burning, pulsating, dull, sharp. Where is it located and does it radiates? Is it acute or chronic and how severe? Does it interfere with partaking in social events or limits what you are able to do? Does it create worries? Pain that can’t be controlled makes you feel miserable regardless of whether you can express or not your feelings to other people. Overall, pain is a uniquely personal experience given to subjective interpretations and on many occasions, difficult to describe.
People with autism have comorbidities that can increase pain severity. Lack of restful or restorative sleep may accentuate your pain regardless of its origin. Interrupted sleep debilitates you physically and, at the same time, exhausts you emotionally. It leaves you with little energy to fight any perceived pain signals. Without proper sleep the immune system becomes hyperactive in such a way as to promote inflammation. According to a randomized controlled in-laboratory study, “Insufficient sleep quantity may facilitate and/or exacerbate pain through elevations of IL-6. In disorders where sleep disturbances are common, insufficient sleep quantity itself may establish and maintain its co-occurrence with pain and increased inflammation” (Haack et al., Sleep 30(9):1145-1152, 2007).
Anxiety disorders, common in autism, intensify pain severity and makes it longer lasting. Also, pain, by itself, is a common symptom of an anxiety disorder, particularly that of a generalized type. A recent study published in March 2018 in the European Journal of Neuroscience showed that autistic individuals anticipation for pain was indirectly correlated to scores in an empathy quotient questionnaire, thus linking anxiety (pain anticipation) to social impairment (Gu et al., 2018). Pain that is perceived as normal by a neurotypical may be overwhelming for autistics. In some cases, a way to protect yourself from pain is to withdraw from social interactions.
Children with autism experience more stomachaches than other children of their own age. They are more likely to develop diarrhea, constipation, and abdominal pain. Strong preference for certain foods, causing dietary changes, may lead to or exacerbate these symptoms. A major concern is the increased association between autism and irritable bowel syndrome. This is an inflammatory disorder of the large intestine characterized by cramping and abdominal pain. Irritable bowel syndrome involves real chronic pain that reduces the quality of life. Patients with irritable bowel syndrome often become depressed and avoid going out, limiting their participation in social activities.
An interdisciplinary unit on pain offers the best treatment opportunities to treat chronic pain. They offer therapy which is adept for multiple purposes to the autistic individual, involving cognitive-behavioral strategies like relaxation training, biofeedback and stress management techniques, and physical reconditioning. It is important to identify and treat coexisting comorbidities (e.g., sleep problems, anxiety). Medications will often be needed, but in the case of chronic pain opioids are avoided. They may cause addiction, depress respiration, and in the case of irritable bowel syndrome exacerbate any attendant constipation. If opioids are needed, a special multidisciplinary clinic may be in the best position to recommend newer medications of kappa opioid agonists and atypical benzodiazepine antagonists.
Gu X, Zhou TJ, ANagnostou E, et al. Heightened brain response to pain anticipation in high-functioning adults with autism spectrum disorder. Eur J Neurosci 47(6)::592-601, 2018.
Haack M, Sanchez E, Mulllington JM. Elevated inflammatory markers in response to prolonged sleep restriction are associated with increased pain experience in healthy volunteers. Sleep 30(9):1145-1152, 2007.
Klintwall L, Holm A, Eriksson M, et al. Sensory abnormalities in autism: a brief report. Research in Developmental Disabilities 32:795-800, 2011.
Zunhammer M, Halski A, Eichhammer P, Busch V. Theory of mind and emotional awareness in chronic somatoform pain patients. PLOSone https://doi.org/10.1371/journal.pone.0140016