Although much about ASDs is not known, the consensus is: the earlier the diagnosis, the earlier interventions and treatment can begin. Evidence over the past decade or more indicate that intensive, early intervention in optimal educational settings for at least two years during the preschool years result in improved outcomes in most young children. Currently, no medical test exists to determine if a child has or will develop an ASD. Therefore, when evaluating a child, clinicians rely on behavioral characteristics to make a diagnosis. Some of the characteristic behaviors of ASDs might be apparent in the first few months of a child’s life, but most often they appear at any time during the early years. A clinical diagnosis would come from an observed problem in at least one of the areas of communication, socialization, or restricted behavior before the age of three.
Diagnosis can be difficult for doctors because ASDs vary widely in severity and symptoms, and may go unrecognized, especially in mildly affected individuals or in those with multiple disabilities. Another consideration is that many of the behaviors associated with autism are shared by other disorders. Therefore, various medical tests may be ordered to rule out or identify other possible causes. For this reason, researchers have developed several sets of diagnostic criteria for ASDs. They include:
Absence or impairment of imaginative and social play
Impaired ability to make friends with peers
Impaired ability to initiate or sustain a conversation with others
Stereotyped, repetitive, or unusual use of language
Restricted patterns of interests that are abnormal in intensity or focus
Diagnosis requires a two-stage process. The first stage involves developmental screening during “well child” check-ups. Several screening instruments have been developed to quickly gather information about a child’s social and communicative development within medical settings.
The second stage of diagnosis must be done by a multidisciplinary team composed of a psychologist, a neurologist, a psychiatrist, a speech therapist, or other professionals who diagnose children with ASDs.