Signs of autism spectrum disorder often manifest in early childhood and often before a child is one year old. Symptoms become consistently noticeable by the time the child is 2 or 3 years old. In some cases, people have such mild symptoms they may not get diagnosed until they start school, and some people don’t get diagnosed until they are in their teen years or adulthood when social deficits become more obvious.
A neurodevelopmental evaluation is required to get an official diagnosis of autism spectrum disorder. However, a parent, teacher, or child therapist can make a referral to a psychiatrist for children or adolescents, a developmental pediatrician, a pediatric psychologist, and/or a child neurologist for a formal evaluation.
The evaluation may involve interviewing the parents or caregivers, and/or teachers, observing and interacting with the child or teen in a controlled and structured setting. Sometimes other tests are administered to rule out other disorders.
A child often fares better in life if diagnosed at a younger age as the child and the family are more likely to receive support services and have better access to community and school resources.
Common Deficits and Symptoms of Autism Spectrum Disorder
According to the Diagnostic and Statistical Manual of Mental Disorders and the American Psychiatric Association’s Diagnostic and Statistical Manual, Fifth Edition (DSM-5) the following are standardized criteria used to diagnose a person with autism: Persistent deficits in social communication and social interaction across multiple contexts, as manifested by the following, currently or by history (examples are illustrative, not exhaustive; see text):
- Deficits in social-emotional reciprocity, ranging, for example, from abnormal social approach and failure of normal back-and-forth conversation; to reduced sharing of interests, emotions, or affect; to failure to initiate or respond to social interactions.
- Deficits in nonverbal communicative behaviors used for social interaction, ranging, for example, from poorly integrated verbal and nonverbal communication; to abnormalities in eye contact and body language or deficits in understanding and use of gestures; to a total lack of facial expressions and nonverbal communication.
- Deficits in developing, maintaining, and understanding relationships, ranging, for example, from difficulties adjusting behavior to suit various social contexts; to difficulties in sharing imaginative play or in making friends; to absence of interest in peers.
Symptoms must be present in the early developmental period (but may not become fully manifest until social demands exceed limited capacities or may be masked by learned strategies in later life). Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning.
These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay. Intellectual disability and autism spectrum disorder frequently co-occur. To make comorbid diagnoses of autism spectrum disorder and intellectual disability, social communication should be below that expected for the general developmental level.
Severity is based on social communication impairments and restricted, repetitive patterns of behavior.