- What are ASDs? -
Autism Spectrum Disorders (ASDs)

What are ASDs?
How do ASDs affect people?
What is the prevalence of ASDs?
Who is affected?
What are the early signs of ASDs?
What causes ASDs?
Why is early diagnosis so important?

What are ASDs?

Autism Spectrum Disorders (ASDs) are complex neurodevelopmental disabilities affecting the normal functioning of the brain. They usually appear during early childhood and typically last throughout a person’s lifetime.

The DSM IV (Diagnostic and Statistical Manual of Mental Disorders) lists five developmental disorders that fall under the Autism Spectrum Disorders heading:

• Autism
• Asperger Syndrome
• PDD NOS (Pervasive Developmental Disorder – not otherwise specified)
• Rett Syndrome, and
• Childhood Disintegrative Disorder.

The general term “autism” is often used either specifically to refer to Autism or more generally to refer to any of the ASDs above. Another term that is frequently used synonymously with ASD is Pervasive Developmental Disorder (PDD).

These conditions are all characterized by varying degrees of impairment in the ability to communicate and function socially, and also by repetitive behaviours.

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How do ASDs affect people?

In general, autism impacts an individual’s ability to communicate and relate to others. Children and adults “on the spectrum” commonly:

• have difficulties with social interactions;
• show impairment in verbal and/or nonverbal communication; and
• develop rigid routines and repetitive, unusual, or highly-specialized interests.

They may also have:

• co-occurring physical conditions such as seizures, sleep disturbances and gastrointestinal difficulties;
• cognitive deficits;
• special abilities in a particular area; and/or
• sensory and motor problems.

The term "spectrum" refers to a continuum of severity or developmental impairment. People with ASDs have communication and social disabilities in common but each person is unique and there is a wide spectrum of individual differences in:

• Symptoms and characteristics (e.g., challenges with social understanding, sensory issues, concurrent physical symptoms, ability to understand language, speak and learn, cognitive abilities, behavioural issues, special abilities);

• Severity: mild (e.g., a person who may be described as “unusual” or “eccentric”) to very severe (e.g., someone suffering from serious sensory discomfort, inability to communicate his/her needs and/or self-injurious or other extreme behaviours); and

• Levels of functioning and independence.

Complex conditions like autism and Aspergers typically present lifelong medical, educational, mental health, financial and social challenges to those individuals diagnosed with these conditions, as well as to their family members and advocates. The treatment, support, service and accommodation needs across the ASD spectrum are multi-faceted.

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What is the prevalence of ASDs?

The Centers for Disease Control & Prevention (CDC) Autism and Developmental Disabilities Monitoring Network (ADDM) in the U.S. currently reports that one in every 70 boys in the United States is affected by autism, and that one in every 110 children has autism spectrum condition. In Canada we do not yet have national ASD surveillance in place but the overall prevalence of autism is consistent world-wide.

Researchers are working to better understand why there are more children being diagnosed with ASD today than ever before. Knowledge of autism has grown, diagnostic criteria have been refined and are being used more frequently which may be resulting in higher prevalence rates but there is no way to know whether increases are due to better diagnostics or real increased risk factors.

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Who is affected?

ASDs affect all racial, ethnic, and social groups and are not a result of income, education level, or parenting styles. They can affect any family – child or adult. ASDs are four times more likely to occur in boys than girls.

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What are the early signs of ASDs?

In the recent past, Autism Spectrum Disorders were usually not diagnosed until the age of three. There is new research showing that children as young as 1 year of age may show signs of an ASD and researchers are even studying the possibilities of diagnosis at as early as 6 months. ASD is diagnosed based on careful observation and assessment of behaviour and knowledge of the child’s or adult’s developmental history. There is no biological or other medical test that can diagnose an ASD.

Parents and caregivers are usually the first to notice something unusual about a child’s interaction or failure to reach the normal developmental milestones. Many parents describe difficulty in getting their pediatricians to take their concerns seriously. They are often told that they are being overly worried and to wait before seeking screening or further investigation. If you have any concerns about your child’ development, it is important to see a developmental pediatrician who is familiar with ASDs.

For more information about indicators for autism and recognizing the early signs of developmental and behavioral disorders, please visit http://www.firstsigns.org or the Centers for Disease Control at www.cdc.gov/actearly.

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What causes ASDs?

At present, the precise mechanisms or “causes” of ASDs are not fully understood. Genetics are thought to play a key role but researchers do not know how many of those on the spectrum have an inherited susceptibility or how many may have ASD caused entirely by genetic factors. Non-heritable risk factors, including environmental factors and mechanisms may also play a large role and may interact with genetic factors by “triggering” autism.

At ASD-CARC we are engaging thousands of families in ASD research. Participation allows us to use essential data to study developmental, genetic and environmental factors important in ASD susceptibility and to better understand different ASD characteristics (phenotypes). Family members, children and adults with autism and related disorders share their first-hand experience allowing our researchers to better understand all the mechanisms and possible causes of ASDs in order to ensure the best individualized treatments and interventions and supports.

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Why is early diagnosis so important?

Early diagnosis should lead to early intervention, or the provision of appropriate and needed supports, which are critical in order for a child diagnosed with an ASD to gain maximum benefit from existing treatments, therapies and interventions. While autism cannot be prevented or “cured”, research has shown that early intervention in an appropriate learning environment can result in significant improvements for many young children with ASDs.

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