A child sits flapping his arms wildly in the air; another expresses his frustration by pushing aside a teacher's aide, a third retreats into playing computer games instead of playing with friends.

All three are showing signs of autism, a common neurological disorder. Autism rates have been rising steadily — even dramatically — in Canada. An estimated 190,000 Canadian children have the disorder. The most recent epidemiological studies suggest that the rate of autism has increased from 40 cases per 100,000 to 60 cases.

Autism was first described in the early 1940s by two doctors who were working independently of each other. Leo Kanner and Hans Asperger identified a set of symptoms they found among the children they were studying. Both used the word autism — from the Greek word for self — to describe the children they treated who seemed enclosed in their own solitary worlds.

Kanner was a child psychologist at Johns Hopkins Hospital in Baltimore; Asperger — whose work was published a year after Kanner's — was a pediatrician in Vienna.

Since Asperger, unlike Kanner, included people who had average to high IQs in his definition, the scientific community has reserved "Asperger syndrome" to describe prodigies and certain high functioning people with autistic disorder. Bill Gates, founder of Microsoft and the world's richest man, is thought by many to have the characteristics of Asperger syndrome. He has often been seen rocking and tends to speak in monotones — both habits acknowledged to be symptoms of Asperger.

Seventy per cent of people with other forms of autistic disorders suffer from mild to severe mental retardation.

What is autism?

The term is used in two ways:

• To refer specifically to Autistic Disorder (classic autism).
• To refer to five Autism Spectrum Disorders described under the diagnostic category of Pervasive Developmental Disorders (PDD) that appear in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) of the American Psychiatric Association.

Autism Spectrum Disorder is a neurological condition that causes developmental disability. It affects the way the brain functions and results in difficulties with communication and social interaction. People with the disorder also exhibit unusual patterns of behaviour, activities and interests.

People with ASDs could share certain behavioural, social and communication characteristics, but they can vary widely in the effect it has on their day-to-day lives. Some people can function well, others are locked in a world of their own. At its most severe, people with autism can exhibit extremely repetitive and unusual behaviours like self-injury and aggression.

If untreated, the symptoms can be very persistent and difficult to change. But in its mildest forms, autism is more like a personality difference linked to difficulties in understanding social conventions.

What are some of the symptoms of ASDs?

There is no single symptom that would lead to a diagnosis of autism. But someone who shows a number of the following characteristics and behaviours would likely be diagnosed with an ASD:

• Shows no interest in other people.
• May be interested in people, but does not know how to talk, play with, or relate to them.
• Initiating and maintaining a conversation is usually difficult.
• Speech and language skills may begin to develop and then be lost, or they may develop very slowly, or they may never develop.
• Difficulty interpreting non-verbal communication such as social distance cues, or the use of gestures and facial cues, like smiles, that most of us take for granted.
• Repeated ritualistic actions such as spinning, rocking, staring, finger flapping, and hitting self.
• Restricted interests and seemingly odd habits, like focusing obsessively on only one thing, idea, or activity.
• Sensory input may be scrambled and overwhelming.

As well, people with ASDs may have secondary problems such as:

• Neurological disorders including epilepsy.
• Gastro-intestinal problems.
• Fine and gross motor deficits.
• Anxiety and depression.

Children with ASDs develop motor, language, cognitive and social skills at different rates from other children their age. For instance, they may be very good at solving math problems but have great difficulty making friends or talking.

How are ASDs diagnosed?

There is no single test that will confirm that someone has an ASD. A diagnosis is based on the number and pattern of typical characteristics and on the observation of specific behaviours and disabilities.

Someone with a mild case could go undiagnosed for years and may only be detected when the person goes through a crisis that brings them in contact with professionals who are able to recognize the disorder.

What causes ASDs?

Nobody's certain. It's generally accepted that autism is a neurological disorder. Research is focusing on genetics, differences in brain function, environmental factors, viral infections and immune responses and deficiencies.

In 2001, a Wired magazine article coined the term "Geek Syndrome" after researchers in California (particularly Silicon Valley) noticed a three-fold surge over 10 years in the number of reported cases of autism.

Researchers have found children with autistic disorders are more common among the offspring of parents in particular careers. In the mid-1990s, clinical psychologist Simon Baron-Cohen compared the professional backgrounds of parents and grandparents of almost 1,000 children with autism to groups of parents of children with Tourette syndrome, Down syndrome and other language delays, and to a control group of parents chosen randomly. His findings showed that the fathers and grandfathers of autistic children were twice as likely to be engineers as the parents of children who were not autistic.

A study published in the journal Nature Genetics on Feb. 18, 2007, pinpointed a new region of DNA thought to cause at least some cases of autism in children. The work involved abnormalities in chromosomes, gene codes and proteins. Between seven and 12 per cent of the families showed individuals sharing possibly detrimental chromosome abnormalities. A linkage analysis that searched for regions of the genome that might be shared by individuals with autism spectrum disorder turned up a region on chromosome 11 that was not previously linked to the risk of developing autism.

How is autism treated?

Some people with mild forms of autism may never need treatment. They can function well and may even excel. However, those with severe forms of the disorder are unable to function and may benefit from active therapy.

There are several ways people with autism are treated and there is plenty of debate over what kinds of treatments offer the most success. Applied Behavioural Analysis (ABA) and Intensive Behavioural Intervention (IBI) are designed to actively engage children with communication, socialization, learning and behavioural problems.

ABA can be extremely expensive as it involves one-on-one teaching for up to 40 hours per week. Costs range from $30,000 to $80,000 a year, according to Autism Society Canada. IBI is also an intensive program that can involve either one-on-one therapy or sessions with small groups.

Other types of therapy can combine elements of physiotherapy, counselling, development of motor and language skills, diet and medication.

Provincial medical plans offer varying levels of coverage for autism therapy. Some will also cover all or part of the cost of intensive ABA and IBI programs.

• Alberta pays up to $60,000 a year per child up to age 18 for ABA/IBA programs.
• Ontario covers ABA/IBI programs for qualifying children under the age of six — older children are also eligible if an assessment determines they need more treatment.
• British Columbia pays up to $20,000 annually for treatment for children up to age six. It pays $6,000 annually for treatment of children six years of age and older.
• Nova Scotia pays for an Early Intensive Behaviour Intervention Program. Direct EIBI is provided over the first six months for 15 hours a week, and is gradually reduced over the following six months (10 hours per week for three months and then five to six hours a week for the remaining three months).
• P.E.I. covers IBI programs for up to $200 per week.
• In New Brunswick, the government will pay for intervention services for a child diagnosed with Autism Spectrum Disorder until the beginning of the school year in the year they turn five.
• Manitoba pays up to $6,000 a year for preschoolers for up to 36 hours of ABA treatment a week, with five hours of that treatment provided by the family.
• Newfoundland and Labrador will pay up to $40,000 a year per child under the age of six for 30 hours a week of ABA/IBI treatment for two years.
• Saskatchewan offers up to 10 hours of therapy under its Autism Early Childhood Therapy Program. In 2006, six children were covered.
• Quebec's Autism Action Plan offers 20 hours a week of ABA/IBI therapy for children between the ages of two and five.
• The Yukon government pays for ABA/IBI treatment for children up to the age of 19, with no yearly maximum.
• The Northwest Territories pays for ABA/IBI treatment for pre-school and school-aged children.
• Nunavut has no specific program for children with autism.

Source for funding details: Library of Parliament