Autism traits: The importance of “co-morbid” problems for impairment and contact with services. Data from the Bergen Child Study

•Children screening positive for autism in the population have many co-occurring problems and high impairment.•The high impairment found is to a large degree accounted for by co-occurring problems.•Co-occurring problems such as learning problems and ADHD predict contact with services.•ASD screen positive girls have as many co-occurring problems but are scored as less impaired.•ASD screen positive girls have less ADHD and ODD but more eating problems and more compulsive–obsessive problems than boys.