Although a single specific cause of autism is not known, current research links autism to biological or neurological differences in the brain. In many families there appears to be a pattern of autism or related disabilities — which suggests there is a genetic basis to the disorder — although at this time no gene has been directly linked to autism.
The genetic basis is believed by researchers to be highly complex, probably involving several genes in combination. Several outdated theories about the causes of autism have been proven false. Autism is not a mental illness. Children with autism are not unruly kids who choose to not behave. Autism is not caused by bad parenting. Furthermore, no known psychological factors in the development of the child have been shown to cause autism.
There are no medical tests for diagnosing autism. An accurate diagnosis must be based on observation of the individual’s communication, behavior, and developmental levels. However, because many of the behaviors associated with autism are shared by other disorders, various medical tests may be ordered to rule out or identify other possible causes of the symptoms being exhibited. Because the characteristics of the disorder vary so much, ideally a child should be evaluated by a multidisciplinary team, which may include a neurologist, psychologist, developmental pediatrician, speech/language therapist, learning consultant, or another professional knowledgeable about autism.
Diagnosis is difficult for a practitioner with limited training or exposure to autism. Sometimes autism has been misdiagnosed by well-meaning professionals. Difficulties in the recognition and acknowledgment of autism often lead to a lack of services to meet the complex needs of individuals with autism. A brief observation in a single setting cannot present a true picture of an individual’s abilities and behaviors. Parental (and other caregivers’) input and developmental history are very important components of making an accurate diagnosis.
At first glance, some persons with autism may appear to have mental retardation, a behavior disorder, problems with hearing, or even odd and eccentric behavior. To complicate matters further, these conditions can co-occur with autism. However, it is important to distinguish autism from other conditions, because an accurate diagnosis and early identification can provide the basis for building an appropriate and effective educational and treatment program. Sometimes professionals who are not knowledgeable about the needs and opportunities for early intervention in autism do not offer an autism diagnosis even if it is appropriate. This hesitation may be due to a misguided wish to spare the family. Unfortunately, this can lead to failure to obtain appropriate services for the child.
Source: Autism Today