The highest risk of autism was found in families with a history of autism, or Asperger's syndrome and other PDDs in siblings, supporting the commonly accepted knowledge that genetic factors are involved in the etiology of autism.

The purpose of this study was to assess the validity of the diagnosis of childhood autism in the Danish Psychiatric Central Register (DPCR) by reviewing medical records from 499 of 504 total children with childhood autism born 1990-1999. Based on review of abstracted behaviors recorded in case records from child psychiatric hospitals, case status determination was performed using a standardized coding scheme. In 499 children diagnosed with childhood autism in the DPCR, the diagnosis could be confirmed in 469 children (94%). Of the 30 non-confirmed cases, five were classified by the reviewers as non-autistic cases and the remaining 25 cases were either classified with another ASD diagnosis or the specific diagnosis was not possible to determine.

PURPOSE-We sought to study the possible association between parental age and autism spectrum disorder (ASD) by using both a cohort design and a sibling design. RESULTS-A total of 9556 children were diagnosed with an ASD. Both maternal and paternal age were associated with a greater risk of ASD in the offspring (hazard ratios ranging from 1.21 (1.10-1.34) to 1.65 (1.09-2.48) depending on combinations of parental age categories; <35, 35-39, and 40+ years). For mothers younger than 35 years, the risk of ASD increased with increasing father's age group. For fathers younger than 35 years, the risk of ASD increased with increasing maternal age. CONCLUSIONS-We found an association between parental age and ASD in the cohort study, but the combined underlying mechanisms through which paternal and maternal age impact ASD risk do not seem to act synergistically. The results of the sibling analysis suggest that the association between parental age and ASD found in the cohort study cannot be accounted for by common genetic and environmental factors. METHODS-Our

The long-term outcome of almost half of all individuals with autistic disorders is poor. The subtype of autism in childhood may be a predictor for specific long-term outcomes, but in general, little is known about the pathways and predictors.

The discontinuation of thimerosal-containing vaccines in Denmark in 1992 was followed by an increase in the incidence of autism. Our ecological data do not support a correlation between thimerosal-containing vaccines and the incidence of autism.

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.

We found that the estimated prevalences of the PDDs studied were probably underestimated. Furthermore, the increasing prevalence and incidence rates during the 1990s may well be explained by changes in the registration procedures and more awareness of the disorders, although a true increase in the incidence cannot be ruled out.

This study investigated time trends and associated factors of incidence rates of diagnosed autism spectrum disorders (ASD) across the lifespan from 1995 to 2010, using data from the Danish Psychiatric Central Research Registry. First time diagnosis of childhood autism, atypical autism, Asperger's syndrome, or pervasive developmental disorder-unspecified (PDD-NOS) were identified, incidence rates were calculated, and data were fitted using non-linear least squares methods. A total of 14.997 patients were identified and incidence rates for ASD increased from 9.0 to 38.6 per 100,000 person years during the 16-year period. The increases were most pronounced in females, adolescents, adults, and patients with Asperger's syndrome and PDD-NOS.