OCD and autism
Children with autism have a higher rate of OCD than children in the typical population.
There is overlap between behaviors seen in children with OCD and the repetitive behaviors commonly observed in children with autism. Children with autism may perform repetitive or ritualistic behaviors, such as ordering, arranging, counting, or touching/tapping. However, children with autism are not likely to think, or obsess, about their repetitive behavior as a solution to a problem, such as a person with OCD would do. Individuals with autism are likely satisfying some other need through their repetitive behavior, such as sensory input or preserving "sameness" in their daily lives.