I do love my quotes on this blog. So another quote to begin this post: "Parent-implemented intervention studies for early ASD thus far have not demonstrated the large effects seen in intensive-treatment studies".
It comes from quite a recent study by Sally Rogers and colleagues* examining "the efficacy of a 12-week, low-intensity (1-hour/wk of therapist contact), parent-delivered intervention for toddlers at risk for autism spectrum disorders (ASD) aged 14 to 24 months and their families". The reported results it seems were less than spectacular in comparison to community treatment as usual bearing in mind the relatively short study duration.
All this comes a few years after the results of PACT (Preschool Autism Communication Trial)** where the authors concluded (sorry more quotes) "we cannot recommend the addition of this PACT intervention to treatment as usual for the purpose of reduction in autism symptoms". PACT by the way is a strategy based predominantly on shared attention, where parents are encouraged to alter their communicative skills more towards their child's level of understanding (see here for a description). I'm not the first to talk about PACT by the way as per this blog entry.
Whilst based on slightly different programmes - Rogers et al looked at a parent-based version of the Early Start Denver Model (ESDM) - a primary focus of both ESDM and PACT are language and shared attention; in both these studies, delivered by parents to young children with autism. Similar to other programs such as the Hanen More Than Words® initiative (itself the subject of some study with autism in mind***) and others****, the suggestion is that subtle alterations to parent - child interactions may ameliorate the presentation of some of the core and peripheral signs and symptoms associated with early infancy autism.
Although not specifically my area of competence, I'm interested in these various studies and results for lots of different reasons, not least some increasing interest in something called VIG (video interaction guidance) albeit not necessarily with parent-child interactions in mind. Seeing parents as partners when offspring autism is present obviously plays a big role in these kinds of initiatives and their associated study. Given the way autism comes about in early infancy, together with the whole brain plasticity and under-connectivity findings***** (full-text), there is sound logic in ensuring the potential gains already noted from early intensive professional intervention****** can also be extended outside of school hours. That and the fact that parents obviously want to do the best they can to help their children's development and symptom presentation (sorry to use such cold terminology by the way).
I don't however think many people would be surprised to hear that when universally applied to all cases of autism, these programs were not entirely effective for all children as per this commentary on the Hanen results. Indeed the same goes for just about any intervention used for autism, even early intensive behavioural intervention (EIBI) if you accept the results from the latest Cochrane review******* on the subject.
That being said, we're potentially back to the old endophenotypes and responder / non-responder suggestions and the growing need for much more research on autisms rather than autism. The fact that response to intervention might be a more suitable 'indicator' for discerning those homogeneous subgroups over the more traditional shotgun approach to multiple targets based on the autism diagnosis alone is another consideration worthy of future discussion.
The question of why the highlighted parent-led interventions don't quite seem to be cutting the statistical mustard is an interesting one. I should at this point demonstrate that other results have indicated some success with home-based programs so we're not talking about a universal failure here bearing in mind some important methodological differences and indeed the targets of such interventions. Other than the reasons already mentioned, there are potentially quite a few other factors at play not least some expected variability in the delivery of the interventions and questions about the outcomes and length of time being studied. It could well be that there is a ceiling effect from such education and behavioural interventions already reached where intensive intervention is already running in the background at school for example.
Outside of the bloomers (or even including the bloomers), we know that there are potentially some great gains to be made from behavioural intervention******* for some children on the autism spectrum and beyond - perhaps also even translating into physiological measures******** - allowing for the fact that much more detailed scientific investigations are required on efficacy and best-responder characteristics. The position of such parent-based programs at a scientific level measured by the current data however, cannot be easily ignored in these evidence-based medicine days. Indeed reliant on the evidence currently available, does this not make a good case for specialist-delivered early intervention to be made more widely available above and beyond the more cost-effective (to the state) parent-led intervention strategies?
* Rogers SJ. et al. Effects of a brief Early Start Denver Model (ESDM)-based parent intervention on toddlers at risk for autism spectrum disorders: a randomized controlled trial. J Am Acad Child Adolesc Psychiatry. 2012; 51: 1052-1056.
** Green J. et al. Parent-mediated communication-focused treatment in children with autism (PACT): a randomised controlled trial. Lancet. 2010; 375: 2152-2160.
*** Carter AS. et al. A randomized controlled trial of Hanen's 'More Than Words' in toddlers with early autism symptoms. J Child Psychol Psychiatry. 2011; 52: 741-752.
**** Soloman R. et al. Pilot study of a parent training program for young children with autism. The PLAY Project Home Consultation program. Autism. 2007; 11: 205-224.
***** Müller RA. et al. Underconnected, but how? A survey of functional connectivity MRI studies in autism spectrum disorders. Cereb Cortex. 2011; 21: 2233-2243.
****** Grindle CF. et al. Outcomes of a behavioral education model for children with autism in a mainstream school setting. Behav Modif. 2012; 36: 298-319.
******* Reichow B. et al. Early intensive behavioral intervention (EIBI) for young children with autism spectrum disorders (ASD). Cochrane Database Syst Rev. 2012; 10: CD009260.
******** Gutstein SE. Empowering families through Relationship Development Intervention: an important part of the biopsychosocial management of autism spectrum disorders. Ann Clin Psychiatry. 2009; 21: 174-182.
********* Dawson G. et al. Early behavioral intervention is associated with normalized brain activity in young children With autism. J Am Acad Child Adolesc Psychiatr. 2012; 51: 1150-1159.
Rogers SJ, Estes A, Lord C, Vismara L, Winter J, Fitzpatrick A, Guo M, & Dawson G (2012). Effects of a Brief Early Start Denver Model (ESDM)-Based Parent Intervention on Toddlers at Risk for Autism Spectrum Disorders: A Randomized Controlled Trial. Journal of the American Academy of Child and Adolescent Psychiatry, 51 (10), 1052-65 PMID: 23021480