A review of the efficacy of the picture exchange communication system intervention.

Preston et al. (2009) looked at every PECS paper they could find. They wanted to know if the system really helps nonverbal kids with autism.

The team pulled studies from 1994 to 2008. They read each one and asked: Did children learn to ask for things? Did speech grow? Did problem behavior drop?

Kids picked up PECS fast. Most learned to hand over a picture to get a toy or snack.

Speech gains were hit-or-miss. Some children spoke more, others did not. Social play and tantrums barely changed unless extra treatments were added.

Cullinan et al. (2001) wrote the first PECS guide. Preston et al. (2009) later showed the steps work in real life.

Danitz et al. (2014) found PECS works best for preschoolers with both autism and ID. This matches the 2009 view that young, nonverbal children gain the most.

Ferreira et al. (2022) added a new twist: when mothers joined sessions, caregiver stress dipped slightly. The 2009 review never looked at parent stress, so this finding extends the story beyond child skills.

Koudys et al. (2025) later proved you can teach parents PECS on Zoom with the same strong results. Preston et al. (2009) had called for easier ways to train adults; telehealth answers that call.

Use PECS when a child has no words. Expect quick requesting success, but plan extra programs if you also want speech or big drops in problem behavior. Pair the system with caregiver coaching, in person or online, to keep gains steady at home and school.