It's an important summary because (a) it highlights how a diagnosis of autism or autism spectrum disorder (ASD) does seem to increase the risk of various 'challenging behaviours' appearing above and beyond what would typically be expected (see here), (b) it illustrates how said behaviours have an important impact both on the person themselves and significant others around them (see here), and (c) it details 'what might help' in terms of parents or significant others managing such behaviour(s) as well as providing a road map for further study and potentially, further guidance.
The O'Nions paper is open-access so you can read for yourself what the findings were. The main points as I saw them were:
- Challenging behaviours covers a lot of ground.
- Said behaviours can and do affect quality of life for all concerned.
- Various strategies are employed by parents to cope with such behaviours including "accommodating the child... modifying the environment... providing structure, routine and occupation... managing non-compliance with everyday tasks and activities... [and] managing distress."
- Strategies for 'dealing' with such behaviour(s) often take into account their effects not only on the person/child concerned but also the family unit.
What's missing from this review? Well, accepting that the focus was "to identify how parents and caregivers spontaneously manage problem behaviour in ASD" I found the O'Nions paper to be rather light on anything not related to behaviour and/or psychology. Take for example, the growing realisation that challenging behaviour(s) seem to show some connection to sleep patterns in the context of autism  and what that could mean for intervention(s) to manage sleep issues for example (see here). Similarly, the idea that challenging behaviours can, on some occasions, seem to be linked to the experience of pain (see here) and/or fatigue (see here) is perhaps something else important to reiterate, as part of a suite of potential factors to consider (see here). I might also add that a certain type of pain/discomfort (e.g. gastrointestinal) together with sleep issues in the context of autism have been a source of some joint inquiry (see here). There is also a case for further research looking at targeted pharmacotherapy in the context of some challenging behaviours too (see here) with appropriate concerns and caveats noted.
There is another aspect raised by the O'Nions review that also needs to be mentioned: "This analysis shows that many of the strategies used by parents of children with ASD are specifically targeted to manage particular vulnerabilities (e.g., sensory sensitivities, rigidity, insistence on sameness), or accomplish particular behavioural goals, and may be relatively unique to this population." I stress of course, the idea that the core features of autism / ASD seem to be 'targets' of intervention in this area illustrating the link between core behaviours and challenging behaviours. Although I've made quite a big thing on this blog about how 'comorbidity' appearing alongside autism is probably not just comorbidity (see here), I'm taking a slightly opposite view on this occasion, and suggesting that one also needs to be mindful that issues such as anxiety and depression may very well exert an effect on the presentation of challenging behaviour(s) and perhaps need to be looked at separately?
And whilst we're on the topic of challenging behaviours in the context of autism, the review of social outcomes for a sample of adults with autism published by Megan Farley and colleagues  provides some further interesting discussions on this topic. Specifically that: "most participants were only aggressive in response to frustrating situations or when experiencing problems with medical conditions." There's [seemingly] always a reason...
 O'Nions E. et al. How do Parents Manage Irritability, Challenging Behaviour, Non-Compliance and Anxiety in Children with Autism Spectrum Disorders? A Meta-Synthesis. J Autism Dev Disord. 2017. Dec 8.
 Cohen S. et al. Sleep patterns predictive of daytime challenging behavior in individuals with low-functioning autism. Autism Res. 2017 Dec 1.
 Farley M. et al. Mid-life social outcomes for a population-based sample of adults with ASD. Autism Res. 2017 Dec 20.