The ADT is composed of 35 items based on the presence or absence of specific behaviours. Twenty-six items are considered critical and used for screening purposes. The ADT is to be completed by mainstream nursery school teachers but remains scored and interpreted by second level child specialists (e.g. child neurologists/psychiatrists). Nonetheless, in the absence of a reference doctor, the ADT can also be used by paramedicals (e.g. psychologists), child prevention/protection teams, (school) mental health services or any other services in contact with children presenting an atypical development. Fast and easy to use, the ADT informs clinicians about the necessity to address children at risk of ASD to specialised diagnostic teams. In the countries where no screening process exists, the ADT can be used by autism diagnostic teams to quickly evaluate the relevance of multidiscipinary assessment or determine assessment priorities.