Autism is a developmental disability that usually shows symptoms between 18 and 36 months. Autism affects children in many different ways and, as a result, is medically referred to as a "spectrum disorder."

More than 500,000 people in the United States have been diagnosed with autism; it may occur in as many as one in 500 individuals and is four times more prevalent in boys than girls. In the last 5 years, autism has become the third most common form of developmental delay, and now occurs more commonly than Down syndrome. Because there is nothing abnormal about the child's physical appearance, this disorder can be difficult to recognize.

Causes
There is no one specific cause of autism. Current research focuses on biological and neurological differences in the brain, including biochemical imbalances, genetic influences, and immunologic problems. Food allergies, excessive amounts of yeast in the digestive tract, and exposure to environmental toxins have all been implicated.

Symptoms
Children exhibit mild to severe symptoms of delay, in many combinations and varying degrees of severity, although in all cases, the ability to communicate and social interaction are the most impaired functions.

About half of all children with autism have slowed development, especially in language and social skills. The other half develop fairly typically until 18 to 36 months and then begin to regress in speech patterns and social skills. Speaking is often limited to a few repeated or "echoed" words or phrases; some children stop speaking altogether. Some children with autism withdraw from physical contact with other people and do not make eye contact.

Children with autistic characteristics prefer to play alone and seldom play fantasy/imaginary games. Many autistic children engage in repetitive movements like rocking or hand flapping, and they sometimes have tantrums with self- inflicted injuries. There is also marked resistance to change in daily routines and unusual responses to many sensory experiences, especially to some auditory stimuli like sudden, loud noises or high-pitched sounds. They may be obsessed with predictable rituals and sometimes play with only one part of a toy.

But some children with autism have just a few of these symptoms and appear to be developing within typical expectations, although somewhat slowly.

Diagnosing Autism
Autism cannot currently be detected at birth or through any prenatal screening. There does appear to be a genetic link, however; parents of a child with autism have an 8% to 10% chance of having another child with the same disorder or a similar disorder.

Because autism is difficult to recognize and diagnose, it is important that families seek an evaluation by a medical professional experienced in diagnosing and treating the disorder.

"Seek an evaluation as soon as possible. There is a lot of evidence that if something is wrong, early intervention gets the best results. If your child is nearing 18 months or 2 years old and is not gesturing, it may indicate a breakdown in communication development," says Robert Naseef, PhD, the father of a son with autism and a family psychologist who specializes in working with families of children with disabilities.

Susan Stine, MD, a developmental pediatrician, advises parents to "closely document your observations and report them to your pediatrician, who can then advise you regarding further referrals." Physicians will order any indicated medical tests and will prescribe appropriate medications if needed. You may be referred to a developmental pediatrician, a pediatric psychiatrist, or a pediatric neurologist for the diagnosis.

A multidisciplinary team composed of a specialist physician, a pediatric psychologist, a speech/language pathologist, an occupational therapist, and a special education teacher or early childhood educator may all work with you to assess your child's development and behavior and plan a treatment program.

Helping Your Child
You play an extremely important role in helping your child develop. Like other children, children with autism learn primarily through play. "Join your child where he is, in play that is mutually enjoyable," Dr. Naseef says. "With autism, the trick is to pull kids through their repetitive behaviors and rituals, and guide them to activity with more variety. For example, you can pace around the room with them, but then lead them into another room. You need to enter their world to help guide them into yours."

Verbal praise for work well done is sometimes meaningless for children with autism. Find other ways to reinforce good behaviors and promote self-esteem. After your child has successfully completed a task, for example, give him extra time to play with a favorite toy.

Children and adults with autism learn better when information is presented visually as well as verbally. Incorporate "augmentative communication" into your daily routines by combining the spoken word with the presentation of photographs, symbols, or gestures to help your child make his needs, feelings, and ideas known.

"Our goal for every child is for them to speak," says Jean Ruttenberg, executive director of the Center for Autistic Children in Philadelphia, Pennsylvania. "But part of autism is that they don't play well, and all children learn vocabulary through play. We always speak to the children, but we use all means of communication with them - gesture, pictures, symbols, sign language, technology." Daily schedules, favorite foods and activities, and friends and family members can be part of the picture system, assisting children to communicate with the world around them.