Autism Spectrum Disorder refers to a group of pervasive developmental disorders; diagnostic criteria include communication problems, ritualistic behaviours and inappropriate social interaction. Autism is a disorder of brain function that appears early in life, generally before the age of three. Children with autism have problems with social interaction, communication, imagination and behaviour. Autistic traits persist into adulthood, but vary in severity. Some adults with autism function well, earning university degrees and living independently. Others never develop the skills of daily living, and may be incorrectly diagnosed with a variety of psychiatric illnesses. The cause of Autism is not known at the time of this writing but there have been several theories posited which will be discussed throughout the following sections.

Click here to find out more about Autism Spectrum Disorder and what to look out for if you are concerned about your child.

The definitions in the following section have been collected from a number of online encyclopaedia and medical resources. They are merely a description of the most common symptoms and characteristics of ASD. We understand that if you are new to the world of Autism that some of the descriptions offered on the internet can seem very bleak and we have tried to be factual whilst highlighting some of the more positive aspects that children and adults can manifest despite the hurdles that they face.

Infantile Autism

Infantile Autism was first described by Leo Kanner, and it is the usual pattern of neurological development in an autistic person. The person never develops the typical neurology for their age, instead developing characteristically autistic neurology. Certain autistic symptoms are present from birth, but the most obvious symptoms are only detectable at an age when a non-autistic child would start to speak. Most autistic children either never develop speech or have it significantly delayed, and may continue to communicate in a characteristically unusual manner.

Regressive Autism

The alternative to early infantile autism is regressive autism, in which neurological development superficially appears normal for the first 18 months or so and then switches to the autistic pattern. When most people think of autism in children below the age of two years, they think of early infantile autism. In both cases the child is autistic well before birth, and the difference is only in the onset of symptoms.

High Functioning Autism

High-functioning autism (HFA) is the condition of individuals who display symptoms of autism and are able to function close to a normal level in society. Generally, the social difficulties created by their autism do not adversely impact their ability to interact with others on a day-to-day basis. Asperger syndrome is sometimes used in the same thought as HFA, and the exact difference between autism, Asperger's syndrome, and HFA varies from person to person.

In general, people with HFA tend to make fairly frequent social errors involving an inability to predict another persons thoughts, feelings or reactions to something possibly said, much like someone with autism might do. However, these difficulties do not manifest to the extent of full autism or Asperger's syndrome. People with HFA are sometimes articulate, intelligent, gifted, and hard workers when interested in a task, and excellent problem solvers but they may appear somewhat removed or disconnected at times, especially in situations of sensory overload, or perceive extreme social pressure in situations such as during a party.

Low Functioning Autism (Classic Autism)

The more severely affected end of the autistic spectrum is what is known as "low functioning" autism. Usually, low functioning autistic children have little or no language, some degree of mental retardation, little awareness of other people and expectations, and many stereotypes and other odd behaviours. Self injurious behaviour is much more common in low-functioning autistics than in their high-functioning counterparts. Sometimes a child who seemed to be low-functioning in childhood eventually gains language and some awareness of the world and social norms and will move towards the high functioning end of the spectrum. So there is hope as determining a child's IQ under the age of 3 years is very difficult.

Asperger Syndrome

Asperger syndrome (sometimes called Asperger's syndrome, AS, or the more common shorthand Asperger's), is characterised as one of the five pervasive developmental disorders, and is commonly referred to as a form of high-functioning autism. In very broad terms, individuals with Asperger's have normal or above average intellectual capacity, and atypical or poorly developed social skills, often with emotional/social development or integration happening later than usual as a result. It is possible for children who previously were diagnosed as autistic but show progress to be reclassified as AS. The term "Asperger's syndrome" was coined by Lorna Wing in a 1981 medical paper. She named the syndrome after Hans Asperger, an Austrian psychiatrist and paediatrician who himself had used the term autistic psychopathy.