A world-leading autism expert is demanding Executive ministers take action to improve support and services.
About 200 children every month are referred for an autism diagnosis in the north, but more than 2,000 children are waiting to be seen.
Professor Karola Dillenburger from Queen's School of Education said these children and their families faced a higher risk of poverty and inequality.
Prof Dillenburger is the author of a new report on autism, which makes recommendations for the transformation of policy and practice.
She found that while Department of Health figures stated about two per cent of schoolchildren had autism, survey data suggested the actual figure may be higher. Adult autism rates are unknown.
Children with autism miss school 8-13 days per year more than other children, while 20 per cent are bullied 20 per cent are frequently excluded, for example from certain activities or being asked to stay at home when there are school trips.
Prof Dillenburger said early diagnosis and intervention was vital.
"The evidence suggests that at the moment the scales are tipped firmly against individuals with autism towards poverty rather than equality and inclusion. The key to rebalancing the scales lies in early diagnosis and early intensive behavioural intervention for children with autism, and improved training for those who work in education and health services," she said.
"There is extensive and unequivocal evidence that early intensive interventions, based on Applied Behaviour Analysis, can enhance the quality of life of individuals with autism and their families and result in significant cost savings.
"The time taken to refer children and from referral to diagnosis means that these children are not being reached early enough, when brain plasticity is greatest and interventions are likely to have the greatest impact. Without this the outlook is bleak."