Autistic traits and risk of suicidality: ALSPAC opines...

The findings reported by Iryna Culpin and colleagues [1] observing that: "Social communication impairments are an important autistic trait in relation to suicidality" return me back to a topic that features much too frequently on this blog: suicide risk and autism.

Drawing on data from the Avon Longitudinal Study of Parents and Children (ALSPAC) initiative, that continues to provide some important insights on labels like autism (see here for example), researchers sought to answer a couple of important research questions: "1. Is an autism diagnosis and/or autistic traits associated with suicidal ideation (suicidal thoughts and plans) and suicidal behaviour (self-harm with and without suicidal intent) by age 16 years? 2. Are any of the observed associations explained by depressive symptoms in early adolescence?"

The question of whether autism or autistic traits are *associated* with suicide (ideation and/or behaviour) is something that has entered the peer-reviewed research psyche quite a bit in recent times. I've talked for example, about data from 'big data' Taiwan on this topic (see here) who concluded that: "ASD [autism spectrum disorder] was an independent risk factor of attempted suicide" [2] based on the analysis of over 5000 young people diagnosed with autism and some 22, 000 not-autism controls.

The numbers included in the Culpin study were a little less impressive - "5,031 members of the UK-based birth cohort study-the Avon Longitudinal Study of Parents and Children" - but ALSPAC does have the advantages of "long-term follow-up, the availability of data on several outcomes, as well as rich data on confounders, and longitudinal design that enables to examine mediating pathways." Indeed, as well as focusing on a diagnosis of autism, Culpin et al also had some 'rich data' on the presence of "four dichotomised ASD traits (social communication, pragmatic language, repetitive behaviour, sociability)." This enabled them to both observe any findings based on a diagnosis / label of autism or ASD and also traits pertinent to a diagnosis of autism or ASD. Issues such as self-harm and/or suicidal thoughts or plans were similarly sought from participants at age 16 years based on answers to questions such as "Have you ever hurt yourself on purpose in any way (e.g., by taking an overdose of pills or by cutting yourself?)" and "On any of the occasions when you have hurt yourself on purpose, have you ever seriously wanted to kill yourself?"

Results: as per the opening sentence, authors observed that "social communication difficulties may be important in relation to suicidality." They interpret this by suggesting that their results tally with others where "social impairments and difficulties in establishing interpersonal relationships are triggers for suicidal behaviour."

But... when it came to examining the diagnosis of autism or ASD in relation to suicidality, they reported that there was: "no evidence of an association between ASD diagnosis and any of the outcomes." They caution however that the numbers of those with a diagnosis were "very low and confidence intervals wide." I also note that data on the numbers of those with a diagnosis of ASD with self-harm with or without suicidal intent are shown as 'censored' to "prevent disclosure due to small cell counts."

Finally, it's worthwhile noting another part of the Culpin study analysis looking at a role for depressive symptoms on the observations made. We are told that "data from the Short Mood and Feelings Questionnaire (SMFQ), a 13-item instrument used to evaluate core depressive symptomatology in children aged 8 to 18 years" was also analysed. Authors report on "evidence of an indirect pathway from impaired social cognition to self-harm via depressive symptoms" but such depressive symptoms only accounted for about a third of the "total estimated association between impaired social cognition and self-harm." Enough however for them to conclude that "addressing the mental health needs of children with autism" *might* offset some risk in this area. Who would argue with that?

There are issues with the Culpin study insofar as the focus on self-report over clinical diagnosis for something like depression or depressive symptoms and "limitations in establishing suicidal intent accompanying self-harm, particularly using self-reports which could be influenced by fluctuations in mood or change over time." I will, once again, reiterate that the report of no evidence of of an association between a diagnosis of autism or ASD and suicidality is also likely to be "imprecise due to small numbers."

A final question: by tackling and hopefully influencing "impairments in social communication" alongside other interventions, is it possible that the risk of suicidality in relation to autism can be reduced? I say this bearing in mind that future studies in this area might want to take a larger view of autism (see here) on the basis that a diagnosis of autism rarely exists in a diagnostic vacuum (see here). How also, issues such as depression like various other quality-of-life-draining facets that seem to be over-represented in relation to autism (see here), may very well be a lot more 'core' over 'comorbidity' (see here) at least for some.

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[1] Culpin I. et al. Autistic Traits and Suicidal Thoughts, Plans and Self-Harm in Late Adolescence: Population-Based Cohort Study. J Am Acad Child Adolescent Psychiatry. 2018. March 14.

[2] Chen MH. et al. Risk of Suicide Attempts Among Adolescents and Young Adults With Autism Spectrum Disorder: A Nationwide Longitudinal Follow-Up Study. J Clin Psychiatry. 2017 Nov/Dec;78(9):e1174-e1179.

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