Communication in Autism Spectrum Disorder: What the Research Tells Us

Source: Brignell et al., Cochrane Database of Systematic Reviews (2018); supplemented by Theodoratou (2024) and practitioner resources from Indiana University IRCA and LeafWing Center Evidence level: Tier 1 — Systematic Review (primary source), with Tier 2–4 supporting sources Domain: Communication

• Communication challenges are common, but varied. Around 25–30% of autistic children do not develop functional spoken language or remain "minimally verbal" (using fewer than 30 words). For those who do develop speech, difficulties with social communication — such as taking turns in conversation, understanding non-literal language, and reading non-verbal cues — remain very common.

• No single intervention has been shown to work for all children. A thorough Cochrane systematic review found only two high-quality trials of communication interventions for minimally verbal children with ASD. One used Picture Exchange Communication System (PECS) and one used a home-based play programme (FPI). Both showed some short-term gains in certain communication skills, but neither produced improvements that were clearly maintained over time for most children. The overall quality of evidence was rated very low.

• Some children respond better to certain approaches than others. Early language ability appears to matter: in the play-based FPI study, children with very low expressive language at the start made more progress. In other studies, children's joint attention skills and imitation abilities helped predict who benefited from which type of therapy.

• A range of tools and strategies show promise. Augmentative and Alternative Communication (AAC) tools — including picture boards, sign language, and speech-generating devices — can help children communicate even when speech is limited, and research suggests AAC does not hinder spoken language development. Other well-supported strategies include Functional Communication Training (FCT), Pivotal Response Training (PRT), video modelling, and social skills training.

• When ADHD and ASD co-occur, communication challenges are amplified. Research suggests 50–70% of autistic individuals also have ADHD traits. The combination can make conversation harder — for example, impulsivity may lead to interrupting, while inattention makes sustained back-and-forth exchanges more difficult.

• Early support matters, and it is worth seeking it sooner rather than later. Research consistently suggests that children who develop communication skills before age five tend to have better long-term outcomes. If you have concerns about your child's communication, speaking to a speech-language pathologist early is one of the most helpful steps you can take.

• There is no one-size-fits-all answer — and that is okay. Your child's profile is unique, and the right mix of strategies may look different from another family's. Approaches like AAC, visual supports, and structured communication practice (such as FCT or PECS) can all be valuable starting points, and a qualified therapist can help you identify what fits best.

• You are a key part of your child's communication journey. Parent-mediated approaches — where caregivers learn strategies to use at home — are a growing and promising area of research. Simple things like following your child's lead, using visual schedules, and giving extra processing time can support communication in everyday moments.

• Progress may be gradual, and that is normal. The research shows that communication development in autistic children is often non-linear and highly individual. Monitoring progress over time with your child's therapy team helps ensure that support is adjusted as your child grows.

• The highest-quality evidence is limited. The Cochrane review — the most rigorous source available — found only two qualifying trials for minimally verbal children, both small and with methodological limitations. This does not mean interventions do not help; it means we do not yet have strong proof about which interventions work best, for whom, and for how long.

• Many widely used approaches still lack large-scale RCT evidence. Practices such as ABA, social narratives, and naturalistic language strategies have good supporting evidence, but the evidence base varies in quality. Always ask your therapist what research supports the approach they are recommending.

• This summary cannot replace professional assessment. Every autistic child is different. A speech-language pathologist, autism specialist, or multidisciplinary team is best placed to assess your child's individual communication profile and recommend a tailored plan. If you are concerned about your child's communication development, please seek a professional evaluation.

https://pmc.ncbi.nlm.nih.gov/articles/PMC6516977