Q: My son just turned two and I'm concerned because he isn't talking and rarely makes eye contact with me when I talk to him. Could he be autistic? What exactly is autism and how is it diagnosed?

A: "Autism is a developmental disability that typically appears during the first three years of life," said Joseph Ricciardi, Psy.D., clinical director of the May Center for Early Childhood Education in Arlington, a school for children with autism and other developmental disabilities. "It is a neurological disorder that affects the development of the brain, causing difficulty with communication, learning, and social interaction."

According to Ricciardi, symptoms of autism include language that is slow to develop, lack of sociability, and unusual repetitive behaviors.

"There are no medical tests for diagnosing autism, but when parents become concerned about developmental delays in their children, they should consult their pediatrician," said. Ricciardi. "Your doctor can rule out various potential medical causes for developmental delays such as hearing and/or voice problems. Before a child can be diagnosed with autism, he or she should be evaluated by a multi-disciplinary team that may include a neurologist, psychologist, developmental pediatrician, speech/language therapist, learning specialist, or another professional knowledgeable about the disorder."

Although one specific cause has not been identified, current research links autism to biological or neurological differences in the brain. It is believed to have a genetic basis, but a particular gene has not been directly linked to the disorder. Researchers are using advanced brain-imaging technology to examine environmental factors that may contribute to the development of autism. MRI (Magnetic Resonance Imaging) and PET (Positron Emission Tomography) scans can show abnormalities in the structure of the brain, with significant cellular differences in the cerebellum.

"Autism and other pervasive developmental disorders (PDDs), such as Asperger Syndrome, occur in approximately one in 500 individuals," Ricciardi explained. "The number of identified cases of autism is on the rise, and it is now the fourth most common developmental disability, following mental retardation, blindness, and cerebral palsy. It is five times as common as Down syndrome and four times more likely to occur in boys than in girls."

"Most researchers agree that the sooner an autistic child begins an intervention program, the better," Ricciardi added. "At this time, the best approach for the treatment of autistic children involves special educators, psychologists, speech and occupational therapists. Although medications are sometimes used to manage problematic features of autism, there are currently no medications that effectively treat the core symptoms."

A mainstay of an effective intervention program is applied behavior analysis or ABA. In ABA, scientifically established principles of learning and behavior are combined to address the primary areas of concern in autism: communication, social development, learning, and behavior problems.

Ricciardi recommends that parents look for a program that provides direct consultation by senior clinicians, an experienced staff, and approaches, such as ABA, that are referenced in professional literature. "In addition," he said, "families should strive to create a professional working relationship with educators and clinicians. Autism is a long journey, and a partner can make all the difference. Look for professionals who are knowledgeable, caring, and can work well with school administrators."