There was no evidence that AAC improved frequency of speech , verbal expressive vocabulary or children 's social communication or pragmatic language immediately postintervention .
Overall , neither of the interventions ( PECS or FPI ) result ed in maintained improvements in spoken or non-verbal communication in most children .
AUTHORS ' CONCLUSIONS There is limited evidence that verbally based and ACC interventions improve spoken and non-verbal communication in minimally verbal children with ASD .
In the study that used an AAC intervention , there were significant gains in frequency of PECS use and verbal and non-verbal initiations , but not in expressive vocabulary or social communication immediately postintervention .
In the study that investigated a verbally based intervention , there were no significant gains in expressive language postintervention , but children with lower expressive language at the beginning of the study improved more than those with better expressive language at baseline .
Neither study investigated adverse events , other communication skills , quality of life or behavioural outcomes .
BACKGROUND Autism spectrum disorder ( ASD ) has an estimated prevalence of around 1.7 % of the population .
People with ASD often also have language difficulties , and about 25 % to 30 % of children with ASD either fail to develop functional language or are minimally verbal .
The ability to communicate effectively is an essential life skill , and difficulties with communication can have a range of adverse outcomes , including poorer academic achievement , behavioural difficulties and reduced quality of life .
Historically , most studies have investigated communication interventions for ASD in verbal children .
We can not assume the same interventions will work for minimally verbal children with ASD .
OBJECTIVES To assess the effects of communication interventions  for ASD in minimally verbal children .
Intervention targeting development of socially synchronous engagement in toddlers with autism spectrum disorder: a randomized controlled trial.
BACKGROUND Social and communication impairments are core deficits and prognostic indicators of autism . We evaluated the impact of supplementing a comprehensive intervention with a curriculum targeting socially synchronous behavior on social outcomes of toddlers with autism spectrum disorders ( ASD ) . METHODS Fifty toddlers with ASD , ages 21 to 33 months , were r and omized to one of two six-month interventions : Interpersonal Synchrony or Non-Interpersonal Synchrony . The interventions provided identical intensity ( 10 hours per week in classroom ) , student-to-teacher ratio , schedule , home-based parent training ( 1.5 hours per month ) , parent education ( 38 hours ) , and instructional strategies , except the Interpersonal Synchrony condition provided a supplementary curriculum targeting socially engaged imitation , joint attention , and affect sharing ; measures of these were primary outcomes . Assessment s were conducted pre-intervention , immediately post-intervention , and , to assess maintenance , at six-month follow-up . R and om effects models were used to examine differences between groups over time . Secondary analyses examined gains in expressive language and nonverbal cognition , and time effects during the intervention and follow-up periods . RESULTS A significant treatment effect was found for socially engaged imitation ( p = .02 ) , with more than doubling ( 17 % to 42 % ) of imitated acts paired with eye contact in the Interpersonal Synchrony group after the intervention . This skill was generalized to unfamiliar context s and maintained through follow-up . Similar gains were observed for initiation of joint attention and shared positive affect , but between-group differences did not reach statistical significance . A significant time effect was found for all outcomes ( p < .001 ) ; greatest change occurred during the intervention period , particularly in the Interpersonal Synchrony group . CONCLUSIONS This is the first ASD r and omized trial involving toddlers to identify an active ingredient for enhancing socially engaged imitation . Adding social engagement targets to intervention improves short-term outcome at no additional cost to the intervention . The social , language , and cognitive gains in our participants provide evidence for plasticity of these developmental systems in toddlers with ASD . http://www . clinical trials.gov/ct2/show/NCT00106210?term = l and a&rank = 3
There was no evidence that AAC improved frequency of speech , verbal expressive vocabulary or children 's social communication or pragmatic language immediately postintervention .
Overall , neither of the interventions ( PECS or FPI ) result ed in maintained improvements in spoken or non-verbal communication in most children .
AUTHORS ' CONCLUSIONS There is limited evidence that verbally based and ACC interventions improve spoken and non-verbal communication in minimally verbal children with ASD .
In the study that used an AAC intervention , there were significant gains in frequency of PECS use and verbal and non-verbal initiations , but not in expressive vocabulary or social communication immediately postintervention .
In the study that investigated a verbally based intervention , there were no significant gains in expressive language postintervention , but children with lower expressive language at the beginning of the study improved more than those with better expressive language at baseline .
Neither study investigated adverse events , other communication skills , quality of life or behavioural outcomes .
BACKGROUND Autism spectrum disorder ( ASD ) has an estimated prevalence of around 1.7 % of the population .
People with ASD often also have language difficulties , and about 25 % to 30 % of children with ASD either fail to develop functional language or are minimally verbal .
The ability to communicate effectively is an essential life skill , and difficulties with communication can have a range of adverse outcomes , including poorer academic achievement , behavioural difficulties and reduced quality of life .
Historically , most studies have investigated communication interventions for ASD in verbal children .
We can not assume the same interventions will work for minimally verbal children with ASD .
OBJECTIVES To assess the effects of communication interventions  for ASD in minimally verbal children .