This is the first randomized study to show positive and generalized effects of preschool-based JA-intervention.

Little is known about use of early interventions for autism spectrum disorder (ASD) in Europe. Parents of children with ASD aged 7 years or younger (N=1680) were recruited through parent organisations in 18 European countries and completed an online survey about the interventions their child received. There was considerable variation in use of interventions and in some countries more than 20% of children received no intervention at all. The most frequently reported treatments were speech and language therapy (64%) and behavioural, developmental and relationship based treatments (55%). In some parts of Europe, use of behavioural, developmental and relationship-based interventions was associated with higher parental educational level and time passed since diagnosis, rather than USE OF INTERVENTION FOR CHILDREN WITH ASD IN EUROPE 2 with child characteristics. These findings highlight the need to monitor use of treatment for children with ASD in Europe in order to contrast inequalities.

This study is the first to show that, similar to specialist-delivered treatment, preschool-based treatment may produce small but possibly clinically important long-term changes in social communication in young children with autism. The treatment did not affect language and global ratings of social functioning and communication. More studies are needed to better understand whether treatment effects may be improved by increasing the intensity and duration of the treatment. Clinical trial registration information--Joint Attention Intervention and Young Children With Autism; http://clinicaltrials.gov/; NCT00378157.

Research on sex-related differences in Autism Spectrum Disorder (ASD) has been impeded by small samples. We pooled 28 datasets from 18 sites across nine European countries to examine sex differences in the ASD phenotype on the ADI-R (376 females, 1763 males) and ADOS (233 females, 1187 males). On the ADI-R, early childhood restricted and repetitive behaviours were lower in females than males, alongside comparable levels of social interaction and communication difficulties in females and males. Current ADI-R and ADOS scores showed no sex differences for ASD severity. There were lower socio-communicative symptoms in older compared to younger individuals. This large European ASD sample adds to the literature on sex and age variations of ASD symptomatology.Electronic supplementary materialThe online version of this article (10.1007/s10803-018-3510-4) contains supplementary material, which is available to authorized users.