Epidemiological studies have shown that a wide range of outcome trajectories exist in ASD, but little is known about their determinant in a long-term perspective. The EpiTED cohort was set-up in order to understand the heterogeneity of developmental trajectories among children with a diagnosis of PDD and the role of clinical, biological and environmental factors in their adaptive outcome. It is one of the rare cohorts involving a long term prospective follow-up based on a large set of variables, and precise phenotypes of the entire autism spectrum.

Purpose: Epidemiological studies have shown that a wide range of outcome trajectories exist in ASD, but little is known about their determinant in a long-term perspective. The EpiTED cohort was set-up in order to understand the heterogeneity of developmental trajectories among children with a diagnosis of PDD and the role of clinical, biological and environmental factors in their adaptive outcome. It is one of the rare cohorts involving a long term prospective follow-up based on a large set of variables, and precise phenotypes of the entire autism spectrum.

Participants: This longitudinal study for which recruitment began between 1997 and 1999, has initially involved 281 preschool aged children recruited from 5 French areas. They were seen at 8 (Time 2), 15 (Time 3) and 20 years of age (Time 4), with an average follow-up length of 15 years. At each follow-up, socio-demographical, clinical, developmental and interventional were collected. At Time 4 (fourth visit), DNA was collected to do a genetic study Findings to date: The main results show that there were two developmental trajectories from childhood to adolescence among the cohort leading to very distinct level of adaptive functioning. Prognosis factors in childhood were the intellectual level, the presence or absence of language, the autism degree and the absence or presence of epilepsy. During adolescence there was a negative impact on the quality of life of the parents of the presence of aberrant behavior and low level functioning, The children included in the cohort were followed during 15 years and were assessed four times (at 5, 8, 15 and 20 years on average, see flow chart in figure 1. From 2000 to 2002, 219 of the original group were reassessed (time 2, T2). At time 3 (T3), between 2007 and 2009, they were 152 to be re-assessed and 106 between 2012 and 2015 (time 4, T4).

Inclusion Criteria:

• Patients previously include in the troop constituted in 1997 /1999 as part of PHRC 96/97 and having been followed during 10 years.
• Patients are 18
• Patients with diagnosis of infantile autism or atypical autism according to the criteria of the CIM 10 at the time of their initial inclusion.

Exclusion Criteria:

• Refusal of participation
• Women pregnant breastfeeding
• persons deprived of freedom by court order