Children with PDD have difficulty with language, communication, socialization, and motor behaviors. Autism is an example of a PDD.

A child with autism appears to live in his or her own world, showing little interest in others and a lack of social awareness.

Autism spectrum disorders, which include autistic disorder, affect children in different ways. Some children have mild symptoms, others have severe limitations.

Learning disorders are sometimes called learning disabilities. Most children with learning disorders have normal intelligence, but they have difficulty with reading, math, or another academic area.

Young children with communication disorders may not speak at all, or may have a limited vocabulary for their age. Some children with communication disorders have difficulty understanding simple directions or are unable to name objects.

Parents of kids with attention-deficit hyperactivity disorder (ADHD) face a tough choice: whether to medicate their children or not.

ADHD is a behavior disorder marked by inattention, impulsivity, and, in some cases, hyperactivity.

Asperger syndrome is similar to autism, another type of childhood developmental disorder, and some doctors consider it to be a high-functioning type of autism.

The odd or inappropriate behaviors, problems with communication, and repetitive routines and rituals that accompany Asperger syndrome can make life challenging for the entire family.

If you are a parent or grandparent of a child with an ASD, it can be heartbreaking if you feel like you just can't connect with him or her. But learning more about these disorders and what has helped others should help you and your relationship.