Autism is one of several types of pervasive developmental disorders (PDDs), also called autism spectrum disorders (ASD). It is not unusual for autism to be confused with other PDDs, such as Asperger’s disorder or syndrome, or to have overlapping symptoms. A similar condition is called pervasive developmental disorder-NOS (not otherwise specified). PDD-NOS occurs when children display similar behaviors but do not meet the criteria for autism. Also, other conditions with similar symptoms may also have similarities to or occur with autism.

Symptoms:

* Significant problems developing nonverbal communication skills, such as eye-to-eye gazing, facial expressions, and body posture.

* Failure to establish friendships with children the same age.

* Lack of interest in sharing enjoyment, interests, or achievements with other people.

* Lack of empathy. People with autism may have difficulty understanding another person’s feelings, such as pain or sorrow.