At T1, before randomization and before treatment commenced the children's language levels were evaluated through two subscales from the Psychoeducational Profile, third edition [PEP-R; (42)] and from an interview with the preschool teachers using two subscales from the Vineland Adaptive Behavior Scales, second edition [VABS-II; (43)]. For the sake of clarity these instruments were also used at T2 representing **data** that has been published elsewhere (37). Mental age was estimated with the Swedish version of the Bayley Scales of Infant and Toddler Development, third edition (44).