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Autism Spectrum Disorder (ASD) is a complex neurobiological developmental disorder that affects the way a person interacts and communicates, as well as the way they learn and behave. Individuals with autism have difficulty with social communication and interaction, and they often have restricted, repetitive patterns of behaviour, interests or activities. Symptoms of autism emerge within the first few years of life, typically by the time the child reaches school age. Significantly more boys than girls are affected by autism, however recent research suggests that there may be subtle differences in girls with autism, often resulting in later or misdiagnosis1.

Autism is called a spectrum disorder to reflect the range of variability in the skills of people diagnosed. Every person with autism is unique, with their own individual strengths and challenges. A person with autism may face challenges at different points in their lifetime, requiring varying degrees of support. 

What are the characteristics of autism?

Communication and social characteristics of autism include difficulties engaging in social interaction and sharing emotions; diminished eye contact; use of gestures and facial expressions; and difficulties in developing, maintaining and understanding relationships. Behavioural characteristics of autism can include repetitive behaviours such as hand flapping or rocking; rigidity in thought and/or behaviour; restricted, intense, or fixated interests; and sensory sensitivities.

These communication, social and behavioural characteristics vary both in the form of impairment and their severity. For example, communication impairment may range from a complete absence of speech to fluent speech but an inability to engage in mutual conversations. Similarly, impairments in behaviour might consist of repetitive speech or non-functional play with objects, insistence on sameness, or distress with change. Individuals with autism may also respond in different ways to sensory input in their environment. 

How is autism diagnosed?

Qualified and experienced professionals use the Diagnostic and Statistical Manual of Mental Disorders – Fifth Edition (DSM-5)2 to make a diagnosis of ASD. The diagnosis is made in consideration of the individual’s developmental history as well as their current skills, strengths and challenges and the impact these challenges have on their daily life and participation. 

What causes autism?

Research into the causes of autism is ongoing – currently there is no one, single known cause. Research suggests there is a strong genetic basis for the condition, however this does not account for all cases3. Researchers are continuing to investigate the role of environmental factors and other potential triggers for autism4,5.

1 Altman, L., & Turk, J. (2016). 1.20 Comparison of Autistic Profiles in Young Females and Males with Autism Spectrum Disorder: A Review of the Literature. (Vol. 55, pp. S106-S106): Elsevier Inc.

2 Diagnostic and statistical manual of mental disorders : DSM-5. (2013).  (Fifth edition. ed.). Arlington, VA: American Psychiatric Publishing.

4 Grabrucker, A. (2013). Environmental Factors in Autism. Frontiers in Psychiatry, 3(118). doi:10.3389/fpsyt.2012.00118

3 Ronald, A., & Hoekstra, R. (2014). Progress in Understanding the Causes of Autism Spectrum Disorders and Autistic Traits: Twin Studies from 1977 to the Present Day (Vol. 2).

5 Whitehouse, A. (2016). What causes autism? What we know, don't know and suspect.   The Conversation. 

6 Young, H., Oreve, M. J., & Speranza, M. (2018). Clinical characteristics and problems diagnosing autism spectrum disorder in girls.(Report). Archives de pediatrie, 25(6), 399. doi:10.1016/j.arcped.2018.06.008