"Video feedback may help babies ‘at risk of autism’" went one write-up of the study results published by Jonathan Green and colleagues  (open-access available here). Continuing a theme of kids at risk of autism potentially 'avoiding' an autism diagnosis (see here) following the use of "a 12-session parent-mediated social communication intervention delivered between 9 and 14 months of age (Intervention in the British Autism Study of Infant Siblings-Video Interaction for Promoting Positive Parenting)" there is some degree of optimism from these latest results together with a pinch of 'not-so-fast'...
Including data from some 54 families - "28 intervention, 26 nonintervention" - researchers reported on the effects of interventions vs. no intervention on various aspects of functioning primarily the "severity of autism prodromal symptoms." Prodromal means early symptoms and is more readily associated with other labels/conditions. The authors reported that results were not completely cut-and-dried in terms of effect(s) of intervention on diagnostic outcome for example (i.e. there were "no intervention effects on diagnostic outcome") but potentially something to see when it comes to the 'severity' of autism prodromal symptoms and "parent-dyad social communication." The authors also noted that measures of communication and language did show something of a trend towards some benefit observed in the intervention group, but did not yield any significant difference when comparing intervention with no intervention over the quite long study period (39 months). This contrasts with their previous results  possibly indicating something rather more adverse when it came to intervention and aspects of language/communication. I might also draw your attention to the fact that from a bank of some 84 families invited to join the study, just over half actually agreed or fulfilled the criteria for joining.
I know this is an area of research that people really want to see work. Alongside other early intervention research in relation to autism (see here for example), the idea that some small adjustments to early interactions might affect the presentation of autism still enjoys quite a lot of support in various quarters. The thing is that these and other results whilst suggesting that things like 'parental responsiveness' can improve as a result of intervention(s), have so far shown that important outcomes for young children are far less impressive. This is something evident across quite a lot of the research literature in this area even when meta-analysed (see here including some chatter about effect sizes).
I'm not suggesting that we everyone just 'gives up' when it comes to early interventions like the one described by Green and colleagues. I do however think science and clinical practice needs to be a little more focused on things like potential best-responders to such interventions (as it does for many other aspects of autism science) and not so focused on creating grand media headlines. I might also throw in the idea that study design is something that needs to be improved particularly in light of other recent findings  talking about how "placebo-like effects represent substantial challenges for randomized controlled trials (RCTs) that use treatment as usual" (guess what many studies in this area use as their comparator?) Accepting that variables such as the plural autisms (see here) are inevitably going to affect results from such studies, I'm minded to suggest that quite a few more resources need to be committed to looking at the possible 'hows and whys' of autism coming about before any talk about early parent-mediated intervention becoming widespread. So, questions like whether screening for inborn errors of metabolism in relation to autism (see here) could be a good first step as part of the mantra 'diagnosis is a starting point not the finishing line' and then taking things from there...
 Green J. et al. Randomised trial of a parent-mediated intervention for infants at high risk for autism: longitudinal outcomes to age 3 years. J Child Psychol Psychiatry. 2017 Apr 10.
 Green J. et al. Parent-mediated intervention versus no intervention for infants at high risk of autism: a parallel, single-blind, randomised trial. Lancet Psychiatry. 2015. Jan 22.
 Jones RM. et al. Placebo-like response in absence of treatment in children with Autism. Autism Res. 2017. 12 April.
Green J, Pickles A, Pasco G, Bedford R, Wan MW, Elsabbagh M, Slonims V, Gliga T, Jones EJ, Cheung CH, Charman T, Johnson MH, & British Autism Study of Infant Siblings (BASIS) Team. (2017). Randomised trial of a parent-mediated intervention for infants at high risk for autism: longitudinal outcomes to age 3 years. Journal of child psychology and psychiatry, and allied disciplines PMID: 28393350