Autism is a complex developmental disability caused by unusual brain development.
It usually appears in childhood, typically within the first three years of life, and continues throughout the person's life. Boys are four times more likely to be autistic than girls.
Children and adults with autism have difficulties with social interactions, verbal and non-verbal communication, and play and leisure activities. They also have unusual ways of reacting to sensations, and with paying attention.
Autism is considered a spectrum disorder. The symptoms and characteristics can vary from mild to severe, and in a variety of combinations. Two children, both diagnosed with autism, can act much differently from one another and have varying degrees of skills.
Autism and other spectrum disorders can occur alone or in combination with other disabilities such as attention deficit hyperactivity disorder, epilepsy, mental retardation, and other conditions.
Unfortunately, the exact cause of autism is unknown, however, brain scans show differences in the shape and structure of the brain in autistic children.
Whatever the cause, it is clear that children with autism are born with it, or born with the potential to develop this disorder. It is not caused by bad parenting nor is it a mental illness, and no known psychological factors in the development of the child have been determined to cause this condition.
A number of theories are being investigated, including the link between heredity, genetics and medical problems. While no one gene has been identified as causing autism, researchers are looking for irregular segments of genetic code that may be inherited.
Although it appears that some children are born with a susceptibility to autism, researchers have not yet identified a single trigger that causes autism to develop.
Research is also being done to investigate the possibility that under certain conditions, a cluster of unstable genes may interfere with brain development resulting in autism, and also that problems during pregnancy or delivery as well as environmental factors such as viral infections, metabolic imbalances, and exposure to environmental chemicals may cause this condition.
Autism tends to occur more frequently than expected among individuals who have certain medical conditions, including Fragile X syndrome, tuberous sclerosis, congenital rubella syndrome, and untreated phenylketonuria (PKU).
The debate between question of a relationship between vaccines, particularly MMR, and autism continues.
Contrary to belief, many children and adults with autism may make eye contact, show affection, smile, laugh, and demonstrate a variety of other emotions, although this usually occurs in varying degrees. They respond to their environment in both positive and negative ways, as do persons without autism.
Some of the characteristics of autism can include:
- Little or no eye contact
- Resistance to change
- Laughing, crying, and showing distress for reasons not apparent to others
- Temper tantrums
- Unresponsiveness to normal teaching methods
- Inappropriate attachments to objects
- Preferring to be alone
- Using gestures or pointing instead of using words to express needs
- Over- or under-sensitivity to pain
- Physical over-activity or extreme under-activity
- Repeating words or phrases in place of normal language
- Difficulty associating with others
- Sustained "off" forms of play, such as spinning objects like wheels on toy cars
- No fear of danger
- Uneven motor skills
- Acting as if deaf although hearing tests are within normal range
In some instances, aggressive and/or self-injurious behavior may be present.