What is Autism?







ASD varies widely in severity and symptoms and may go unrecognized, especially in mildly affected children or when it is masked by more debilitating handicaps.  Very early indicators that require evaluation by an expert include:

  • no babbling or pointing by age 1
  • no single words by 16 months or two-word phrases by age 2
  • no response to name
  • loss of language or social skills
  • poor eye contact
  • excessive lining up of toys or objects
  • no smiling or social responsiveness.

Later indicators include:

  • impaired ability to make friends with peers
  • impaired ability to initiate or sustain a conversation with others
  • absence or impairment of imaginative and social play
  • stereotyped, repetitive, or unusual use of language
  • restricted patterns of interest that are abnormal in intensity or focus
  • preoccupation with certain objects or subjects
  • inflexible adherence to specific routines or rituals.

Health care providers will often use a questionnaire or other screening instrument to gather information about a child’s development and behavior.  Some screening instruments rely solely on parent observations, while others rely on a combination of parent and doctor observations.  If screening instruments indicate the possibility of an ASD, a more comprehensive evaluation is usually indicated.

A comprehensive evaluation requires a multidisciplinary team, including a psychologist, neurologist, psychiatrist, speech therapist, and other professionals who diagnose children with ASDs.  The team members will conduct a thorough neurological assessment and in-depth cognitive and language testing.  Because hearing problems can cause behaviors that could be mistaken for an ASD, children with delayed speech development should also have their hearing tested.

Children with some symptoms of an ASD but not enough to be diagnosed with classical autism are often diagnosed with PDD-NOS.  Children with autistic behaviors but well-developed language skills are often diagnosed with Asperger syndrome. Much rarer are children who may be diagnosed with childhood disintegrative disorder, in which they develop normally and then suddenly deteriorate between the ages of 3 to 10 years and show marked autistic behaviors.

Scientists aren’t certain about what causes ASD, but it’s likely that both genetics and environment play a role.  Researchers have identified a number of genes associated with the disorder.  Studies of people with ASD have found irregularities in several regions of the brain.  Other studies suggest that people with ASD have abnormal levels of serotonin or other neurotransmitters in the brain.  These abnormalities suggest that ASD could result from the disruption of normal brain development early in fetal development caused by defects in genes that control brain growth and that regulate how brain cells communicate with each other, possibly due to the influence of environmental factors on gene function.  While these findings are intriguing, they are preliminary and require further study.  The theory that parental practices are responsible for ASD has long been disproved.

Twin and family studies strongly suggest that some people have a genetic predisposition to autism.  Identical twin studies show that if one twin is affected, there is up to a 90 percent chance the other twin will be affected.  There are a number of studies in progress to determine the specific genetic factors associated with the development of ASD.  In families with one child with ASD, the risk of having a second child with the disorder is approximately 5 percent, or one in 20.  This is greater than the risk for the general population.  Researchers are looking for clues about which genes contribute to this increased susceptibility.  In some cases, parents and other relatives of a child with ASD show mild impairments in social and communicative skills or engage in repetitive behaviors.  Evidence also suggests that some emotional disorders, such as bipolar disorder, occur more frequently than average in the families of people with ASD.

For many children, symptoms improve with treatment and with age.  Children whose language skills regress early in life—before the age of 3—appear to have a higher than normal risk of developing epilepsy or seizure-like brain activity.  During adolescence, some children with an ASD may become depressed or experience behavioral problems, and their treatment may need some modification as they transition to adulthood.  People with an ASD usually continue to need services and supports as they get older, but many are able to work successfully and live independently or within a supportive environment.



