A 5-year-old boy with normal motor skills has severe language delay, shows no interest in interacting with other children or with adults, and spends a lot of time spinning around. The most likely diagnosis for this child is

The most likely diagnosis for this 5-year-old boy with normal motor skills, severe language delay, and stereo typical spinning movements who shows no interest in interacting with others is infantile autism, a pervasive developmental disorder of childhood. In contrast, children with attention deficit hyperactivity disorder (ADHD) show problems paying attention or with excessive activity but not language delay. Children with conduct disorder show behaviors like stealing, truancy, and setting fires. Mentally retarded children may have language delay but interact with others in a relatively normal fashion. Rett syndrome, which involves some behavioral features of infantile autism such as stereotypical movements, is seen only in girls.