Autism
Autism is a complex developmental disability that typically appears during the first three years of life and affects a person’s ability to communicate and interact with others. Autism is defined by a certain set of behaviors and is a "spectrum disorder" that affects individuals differently and in varying degrees.
Autism is the result of a neurological disorder that affects the functioning of the brain, impacting development in the areas of social interaction and communication skills. Both children and adults on the autism spectrum typically show difficulties in verbal and non-verbal communication, social interactions, and leisure or play activities.
Autism is one of five disorders that fall under the umbrella of Pervasive Developmental Disorders (PDD), a category of neurological disorders characterized by “severe and pervasive impairment in several areas of development.”
Every person with autism is an individual, and like all individuals, has a unique personality and combination of characteristics. Some individuals who are mildly affected may exhibit only slight delays in language and greater challenges in social interactions. They may have difficulty initiating and/or maintaining a conversation. Their communication is often described as talking at others instead of to them (e.g., monologue on a favorite subject that continues despite attempts by others to interject comments).
People with autism also process and respond to information in unique ways. In some cases, aggressive and/or self-injurious behavior may be present. Persons with autism may also exhibit some of the following traits:
- Tantrums
- Spinning objects
- Sustained odd play
- No real fear of danger
- Little or no eye contact
- Uneven gross/fine motor skills
- Difficulty in mixing with others
- Obsessive attachment to objects
- Not wanting to cuddle or be cuddled
- Preference to being alone; aloof manner
- Unresponsive to normal teaching methods
- Insistence on sameness; resistance to change
- Apparent over-sensitivity or under-sensitivity to pain
- Noticeable physical over-activity or extreme under-activity
- Repeating words or phrases in place of normal, responsive language
- Difficulty in expressing needs; using gestures or pointing instead of words
- Non-responsive to verbal cues; acts as if deaf, although hearing tests are in normal range
- Laughing (and/or crying) for no apparent reason; showing distress for reasons not apparent to others
For most of us, the integration of our senses helps us to understand what we are experiencing. For example, our sense of touch, smell and taste work together in the experience of eating a ripe peach: the feel of the peach's skin, its sweet smell, and the juices running down your face. For children with autism, sensory integration problems are common, which may throw their senses off (they may be over- or under-active). The fuzz on the peach may actually be experienced as painful, and the smell may make the child gag. Some children with autism are particularly sensitive to sound, finding even the most ordinary daily noises painful. Many professionals feel that some of the typical behaviors of autism, like the ones listed above, are actually a result of sensory integration difficulties.
There are also many myths and misconceptions about autism. Contrary to popular belief, many children with autism do make eye contact; it just may be less often or different from a neuro-typical child. Many children with autism can develop good functional language and others can develop some type of communication skills, such as sign language or use of pictures. Children do not "outgrow" autism, but symptoms may lessen as the child develops and receives treatment.
One of the most devastating myths about children with autism is that they cannot show affection. While sensory stimulation is processed differently in some children, they can and do give affection. However, it may require patience on the parents' part to accept and give love on the child's terms.
Causes
There is no known single cause for autism, but it is generally accepted that it is caused by abnormalities in brain structure or function. Brain scans show differences in the shape and structure of the brain in children with autism versus neuro-typical children. Researchers are investigating a number of theories, including the link between heredity, genetics and medical problems. In many families, there appears to be a pattern of autism or related disabilities, further supporting a genetic basis to the disorder. While no one gene has been identified as causing autism, researchers are searching for irregular segments of genetic code that children with autism may have inherited. It also appears that some children are born with a susceptibility to autism, but researchers have not yet identified a single "trigger" that causes autism to develop.
Other researchers are investigating the possibility that under certain conditions, a cluster of unstable genes may interfere with brain development, resulting in autism. Still other researchers are investigating problems during pregnancy or delivery as well as environmental factors, such as viral infections, metabolic imbalances, and exposure to environmental chemicals.
Environmental Factors
Research indicates that other factors besides the genetic component are contributing to the rise in increasing occurrences of ASD, such as environmental toxins (e.g., heavy metals such as mercury), which are more prevalent in our current environment than in the past. Those with ASD (or those who are at risk) may be especially vulnerable, as their ability to metabolize and detoxify these exposures can be compromised.
Autism and Amino Acids
Many autistic people have low levels of specific amino acids, despite a diet sufficient to support normal levels. DPP IV is found on epithelial cells in the kidney and is responsible for breaking down peptides into amino acids which are then reabsorbed. An absent or non-functioning enzyme could explain lowered levels of amino acids.