Presently, we don't have a medical test that can diagnose autism. Instead, specially trained physicians and psychologists administer autism-specific behavioral evaluations.
Often parents are the first to notice that their child is showing unusual behaviors such as failing to make eye contact, not responding to his or her name or playing with toys in unusual, repetitive ways. For a description of early indicators of autism, see Learn the Signs.
The Modified Checklist of Autism in Toddlers (M-CHAT) is a list of informative questions about your child. The answers can indicate whether he or she should be further evaluated by a specialist such as a developmental pediatrician, neurologist, psychiatrist or psychologist. (Take the M-CHAT here.)
We encourage parents to trust their instincts and find a doctor who will listen and refer their child to appropriate specialists for diagnosis. Unfortunately, doctors unfamiliar with diagnosing autism sometimes dismiss parent concerns, delaying diagnosis and the opportunity for early intervention therapies. Autism Speaks and other autism organizations are working hard to raise awareness of early signs among physicians as well as parents.
From birth to at least 36 months of age, every child should be screened for developmental milestones during routine well visits. When such a screening, or a parent raises concerns about a child's development, the doctor should refer the child to a specialist in developmental evaluation and early intervention. These evaluations should include hearing and lead exposure tests as well as an autism-specific screening tool such as the M-CHAT. Among these screening tools are several geared to older children and/or specific autism spectrum disorders.
A typical diagnostic evaluation involves a multi-disciplinary team of doctors including a pediatrician, psychologist, speech and language pathologist and occupational therapist. Genetic testing may likewise be recommended, as well as screening for related medical issues such as sleep difficulties. This type of comprehensive helps parents understand as much as possible about their child's strengths and needs.
Sometimes an autism spectrum disorder is diagnosed later in life, often in relation to learning, social or emotional difficulties. As with young children, diagnosis of adolescents and adults involves personal observation and interview by a trained specialist. Often, a diagnosis brings relief to those who have long struggled with difficulties in relating socially while not understanding the source of their difficulties. A diagnosis can also open access to therapies and assistive technologies that can improve function in areas of difficulty and, so, improve overall quality of life.