Do communication interventions for verbal children with ASD work the same for minimally verbal children with ASD? Evidence from a systematic review
Autism Spectrum Disorder is characterized by difficulties in social communication, language development, and repetitive, restricted interests and behaviors. Various communication interventions were developed to encourage language development mostly of verbal children with ASD. However, there is little evidence of the effects of communication interventions for ASD in minimally verbal children (having fewer than 30 functional words and/ or being unable to use speech alone to communicate).
The Brignell et al. systematic review aimed to assess the treatment effects for ASD in minimally verbal children. Of 8248 studies, only two (Focused playtime intervention-FPI and Picture Exchange communication System-PECS; N=154, aged 32 months to 11 years) met the authors’ inclusion criteria. The FPI study found no significant effect for the intervention group on spoken communication. However, the children with lower expressive language ability at baseline benefited more from the intervention than those with better expressive language at baseline. The PECS study found significant effect in the frequency of PECS use and verbal and non‐verbal initiations, but not in expressive vocabulary or social communication immediately after postintervention. Neither intervention study resulted in a sustained improvement in spoken or non-verbal communication in most children. Also, neither study investigated adverse events, other communication skills, quality of life, or behavioral outcomes.
The authors of this systematic review concluded that the quality of the evidence of included studies is very low. They emphasized that future RCTs should compare two interventions and contain a control group. It would allow researchers to better understand treatment effects in the context of spontaneous maturation. It would also allow further comparison of different interventions with the investigation of moderating factors.