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 .
Randomized, Controlled Trial of an Intervention for Toddlers With Autism: The Early Start Denver Model
OBJECTIVE : To conduct a r and omized , controlled trial to evaluate the efficacy of the Early Start Denver Model ( ESDM ) , a comprehensive developmental behavioral intervention , for improving outcomes of toddlers diagnosed with autism spectrum disorder ( ASD ) . METHODS : Forty-eight children diagnosed with ASD between 18 and 30 months of age were r and omly assigned to 1 of 2 groups : ( 1 ) ESDM intervention , which is based on developmental and applied behavioral analytic principles and delivered by trained therapists and parents for 2 years ; or ( 2 ) referral to community providers for intervention commonly available in the community . RESULTS : Compared with children who received community-intervention , children who received ESDM showed significant improvements in IQ , adaptive behavior , and autism diagnosis . Two years after entering intervention , the ESDM group on average improved 17.6 st and ard score points ( 1 SD : 15 points ) compared with 7.0 points in the comparison group relative to baseline scores . The ESDM group maintained its rate of growth in adaptive behavior compared with a normative sample of typically developing children . In contrast , over the 2-year span , the comparison group showed greater delays in adaptive behavior . Children who received ESDM also were more likely to experience a change in diagnosis from autism to pervasive developmental disorder , not otherwise specified , than the comparison group . CONCLUSIONS : This is the first r and omized , controlled trial to demonstrate the efficacy of a comprehensive developmental behavioral intervention for toddlers with ASD for improving cognitive and adaptive behavior and reducing severity of ASD diagnosis . Results of this study underscore the importance of early detection of and intervention in autism
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 .