Collaborative play in a mentalisation-based serious game for adults with intellectual disabilities.

BACKGROUND: People with mild to borderline intellectual disabilities often struggle with mentalising and stress regulation because of developmental delays. Mentalisation-based serious games offer an accessible, engaging way to support them. Adding collaborative play may further enhance effectiveness through communicative interaction. METHOD: Participants (n = 82) played the mentalisation-based game 'You & I' with a professional caregiver, matched to RCT data from playing alone. Linear mixed models were used to analyse the data on mentalisation and stress regulation, and social validity was investigated. RESULTS: Collaborative play did not significantly affect mentalising or stress regulation compared to playing alone. Social validity ratings indicated that collaborative play was anticipated and experienced positively. CONCLUSION: Findings should be interpreted considering non-randomisation, limited reliability, and absence of pre-intervention caregiver training. Further research should examine mechanisms linking communicative behaviours to mentalisation and develop reliable instruments for people with mild to borderline intellectual disabilities.