Autism Spectrum Disorders (ASD) are a group of related pervasive developmental disorders (PDD) that show abnormalities in social behavior and communication, highly restricted interests and repetitive behaviors. The three main disorders of ASD are autism, Asperger syndrome and PDD-NOS. Autism spectrum disorders is the new term to describe these pervasive developmental disorders, which symptoms cover a wide spectrum that ranges from mild to severely impaired.
The following pervasive developmental disorders are grouped together as autism spectrum disorders:
- Autism: Children who have been diagnosed with “classical” autism, often show difficulties with social interactions and with forming relationships with peers and adults. While the severity of autism symptoms vary greatly between children with autism, most children with autism also show stereotypical behaviors in addition to the social difficulties. These include hand flapping, resistance to change, compulsive, restricted and repetitive behaviors and sometimes self-injury.
- PDD-NOS: If symptoms don’t match any of the specific autism disorders, a diagnosis of PDD not otherwise specified (PDD-NOS) is frequently given. The symptoms are often milder than autism, with some of the symptoms present and others absent.
- Asperger syndrome is closely related to autism in potential causes and symptoms, however, with Asperger’s there is usually no delay in language development and cognitive development is usually not impaired. Children with Asperger syndrome show impairments in non-verbal communication skills, may appear clumsy and show less empathy toward peers. The syndrome was first described in 1944 by Austrian pediatrician Hans Asperger.
A number of other disorders, such as Rett syndrome, childhood disintegrative disorder and Potocki-Lupski syndrome, exists which symptoms overlap with autism. Potocki-Lupski syndrome is a recently discovered genetic disorder linked to a duplication of chromosome 17, which symptoms include autism. Other health problems associated with Potocki-Lupski syndrome include low muscle tone, difficulties with swallowing and chewing, verbal apraxia (speech delay), hyperactivity, sleep apnea and potential heart problems. Symptoms of Potocki-Lupski syndrome change over time as the child develops. Potocki-Lupski syndrome can be diagnosed by performing a genetic test that can identify the chromosomal duplication.
While autism has a strong genetic link, it is still unclear whether autism is caused by many different genes or by rare mutations. It has been estimated that 1 in 150 children in the US suffer from autism, with approximately four times as many boys than girls being diagnosed. The prevalence of autism has greatly increased during the last two decades, which cannot be explained by genetics and changes in diagnostic guidelines alone. It has therefore been suggested that environmental factors play a role in the development of autism. These environmental factors include heavy metals, solvents, PCBs, chemicals in plastics and sensitivities to food ingredients such as gluten and casein. While often suggested by parents, the controversial role that childhood vaccines may play in the development of autism, has not been scientifically proven.
Autism treatments are frequently focusing on treating the individual symptoms of autism including problems involving sensory integration, speech, behavior and dietary intervention (e.g. a gluten and casein restrictive diet). Treatments can include applied behavior analysis (ABA), speech therapy, social therapy and occupational therapy.
Children with autism who follow a casein and gluten-free diet, may see improvements in their symptoms. Casein (milk protein) has a similar structure as gluten (from wheat) and it has been shown that casein can break down into a peptide called casomorphin, an opioid that is believed to aggravate autism symptoms. However, to-date, no conclusive scientific evidence exists that link dietary casein and gluten to autism symptoms. In addition, many parents of children with autism also believe that many food colorings (as found in candy and soft drinks) can make autism symptoms worse. Simply avoiding food items that contain food coloring, may benefit the management of autism. Frequently, parents have also reported improvement in autism symptoms giving their children supplements such as omega (3,6 and 9) fatty acids found in fish oils and other autism supplements.
