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 .
A pilot randomised control trial of a parent training intervention for pre-school children with autism

Abstract . Few attempts have been made to conduct r and omised control trials ( RCTs ) of interventions for pre-school children with autism . We report findings of a pilot RCT for a parent training intervention with a focus on the development of joint attention skills and joint action routines . Twenty-four children meeting ICD-10 criteria for childhood autism ( mean age = 23 months ) were identified using the CHAT screen and r and omised to the parent training group or to local services only . A follow-up was conducted 12 months later ( mean age = 35 months ) . There was some evidence that the parent training group made more progress in language development than the local services group . However , the present pilot study was compromised by several factors : a reliance on parental report to measure language , non-matching of the groups on initial IQ , and a lack of systematic checking regarding the implementation of the parent training intervention . Furthermore , three parents in the local services group commenced intensive , home-based behavioural intervention during the course of the study . The difficulties encountered in the conduct of RCTs for pre-school children with autism are discussed . Method ological challenges and strategies for future well- design ed RCTs for autism interventions are highlighted
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 .