What's potentially behind self-injury coincidental to autism?

"Alexithymia, depression, anxiety and sensory differences may place some autistic individuals at especial risk of self-injury."

Those were some of the conclusions reached in the paper published by Rachel Moseley and colleagues [1] (open-access) following their investigation of an important topic - non-suicidal self-injury (NSSI) - in relation to autism "without intellectual disability." Self-injurious behaviour (SIB) is not a pleasant topic to talk about, but is important to quite a few people diagnosed as being on the autism spectrum (see here and see here).

Drawing on data provided by over one hundred adults with autism (autistic adults if you prefer), half of whom were categorised as 'current self-harmers', a quarter of whom were 'historic self-harmers' and a quarter of whom were 'non self-harmers', researchers set to work "to examine alexithymia, mentalising impairments, autistic traits and sensory differences" as possible important variables for NSSI. Alexithymia by the way, is described as "the subclinical inability to identify and describe emotions in the self." Researchers utilised several different questionnaires including a tool specifically designed to test for NSSI: The Non-Suicidal Self-Injury Assessment Tool (NSSI-AT), a "comprehensive instrument [that] documents the nature and bodily location of any self-injurious behaviours; their functional utility; their recency, frequency and likelihood of reoccurrence; the age of onset of self-injury; the severity of injuries" among other things. Results were collated and analysed.

Alongside the headline finding that was included in the opening sentence to this post, other interesting details also emerged from the data. So: "Of the 76 current and historic self-harmers, 60 could recall the onset of self-injury at an average age of 15.1 years." Bearing in mind that 15.1 years was an average age of onset, such a finding potentially provides a developmental window when self-harming could maybe be screened for and interventions put in place. Indeed, from what I understand, this is a fairly typical time of onset for self-injury in the general population minus any sweeping generalisations.

Also: "The most common function of NSSI was the regulation of low-energy affective states (depression, dissociation), followed by the regulation of high-energy states such as anger and anxiety." There's an important word in that last sentence - regulation - that needs a lot more inquiry. It implies that self-injury is not just mindless violence against self but might actually serve some sort of purpose. Indeed, other recent papers have also mentioned regulation in the context of self-injury [2] too. Allied to other research suggesting that 'challenging behvaiours' might for example, under some circumstances, also serve a purpose (see here) and how self-injury could present in a variety of ways (see here), and there are leads to follow. Indeed, it could imply that teaching regulatory processes such as those linked to exercise (see here) or the use of meditative techniques (see here) could be worthwhile for some at least.

And just before I leave this topic, I'm minded to bring in another issue that could be investigated in the context of self-injury: interoception and body awareness in the context of autism (see here). Minus any psychobabble, interoception represents "the sense of the physiological condition of the body." It strikes me as possible that a reduced capacity for interoception in relation to autism, as has been talked about in other independent study [3], could be another important variable in the cycle of self-injury and another point of intervention...

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[1] Moseley RL. et al. A ‘choice’, an ‘addiction’, a way ‘out of the lost’: exploring self-injury in autistic people without intellectual disability. Molecular Autism. 2019; 10: 18.

[2] Weiner L. et al. A case study of suicidality presenting as a restricted interest in autism spectrum disorder. BMC Psychiatry. 2019; 19: 126.

[3] Fiene L. & Brownlow C. Investigating interoception and body awareness in adults with and without autism spectrum disorder. Autism Res. 2015 Dec;8(6):709-16.

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Interoception and body awareness in autism

"Interoception: the sense of the physiological condition of the body" [1].

This was an important concept detailed in the paper by Lisa Fiene and Charlotte Brownlow [2] with autism in mind. Looking at how adults diagnosed with an ASD (autism spectrum disorder) "interpret elements of the interoceptive sense, which includes thirst, hunger, temperature, satiety" researchers questioned those on the spectrum (n=74) and asymptomatic controls (n=228) with "self-reported perceptions of body awareness... and thirst awareness" in mind.

Based on data derived from the Body Awareness Questionnaire (BAQ) and Thirst Awareness Scale (TAS), a lower level of of body and thirst awareness was reported for the autism group. Indeed, authors reported "a large effect" when it came to the differences between the groups. Ergo: "difficulty with sensing internal bodily states could theoretically impact on the physical and mental health, social interactions and self-awareness of adults with ASD."

These are potentially very important results. Allowing for the fact that self-report measures were used and that those towards the more 'able' end of the autism spectrum were only included for study, the idea that basic sensations such as hunger and thirst might not always be sensed and acted upon by some on the autism spectrum is a little worrying.

Outside of the reports of issues with response to temperature noted for some on the autism spectrum which may fall into the area of altered interoception, the idea that thirst, hunger and satiety mechanisms might also show some alteration for some potentially taps into quite a few other areas too. One might for example, entertain the idea that issues with interoception might tie into the growing evidence base looking at feeding practices and weight issues with autism in mind (see here), accepting that feeding practices/habits are probably not the only variable related to weight issues (see here). I wonder also if the reported issues with the hormone ghrelin in cases of autism might also show some involvement too (see here). Polydipsia - excessive thirst - also has some research history with autism in mind (see here) that might also require a little more investigation. Examining the issue of interoception and autism with the various sensory issues linked to the diagnosis (see here) is probably a good idea.

Music: Foals - Spanish Sahara.

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[1] Craig AD. How do you feel? Interoception: the sense of the physiological condition of the body. Nature Reviews Neuroscience. 2002; 3: 655-666.

[2] Fiene L. & Brownlow C. Investigating interoception and body awareness in adults with and without autism spectrum disorder. Autism Res. 2015 Mar 25.

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Fiene L, & Brownlow C (2015). Investigating interoception and body awareness in adults with and without autism spectrum disorder. Autism research : official journal of the International Society for Autism Research PMID: 25808391