Autism is a lifelong neurodevelopmental disorder. Autism is roughly four times more prevalent in boys than in girls.
Individuals with autism have difficulties in three main areas:
(1) deficits in social interactions,
(2) impaired verbal and non-verbal communication, and
(3) repetitive, restricted or stereotyped behaviour, interests and activities.
These symptoms are usually present from before 3 years of age.
Autism is often called a spectrum disorder because there are a variety of behaviours and symptoms associated with the disorder and individuals on the spectrum can have varying levels of ability. The broad category autism spectrum disorders (ASD) includes autism, Asperger’s syndrome and PDD-NOS.
Asperger’s syndrome can be seen as a milder form of autism. Individuals with Asperger’s syndrome also have problems with social interaction and show repetitive behaviours or restricted interests, but are not delayed in developing language. Asperger’s syndrome is often only diagnosed later on in childhood, or even in adulthood. Individuals with Asperger’s syndrome may have average or above-average intelligence.
Individuals with pervasive developmental disorder – not otherwise specified (PDD-NOS) also have difficulty with social interaction and verbal or non-verbal communication, or show repetitive and stereotyped behaviours, but do not meet the criteria for any specific pervasive developmental disorder. This may be because of the late onset of problems, symptomatology that is atypical in some way, or having some but not all of the features of autism.
How prevalent are autism spectrum disorders?
One in 150 children, or 66 in 10 000, in the United States are estimated to have an autism spectrum disorder (Centers for Disease Control and Prevention, 2007). Most ASD diagnoses are milder forms of autism such as PDD-NOS and Asperger’s syndrome. Baird and colleagues (2006) found that the prevalence of autism in Britain was 24.8 – 38.9 per 10 000 and the prevalence of all ASDs 116.1 per 10 000. This is still a large increase from the estimate of 1 in 2500 children in the 1970s. It is unclear whether this increase is because of an actual increase in autism cases, changes in diagnostic criteria, greater awareness of autism spectrum disorders, environmental factors, or all of these factors combined.
Individuals with autism may display the following behaviours:
1. Impairment in social interactions, such as
reduced eye contact, facial expressions and use of gestures in social interactions
dislikes, or is indifferent to, being held, cuddled or touched
prefers to play alone
does not respond to being called
little/ no peer relationships appropriate to their developmental stage
little awareness of others and their feelings
2. Impaired verbal and non-verbal communication, such as
delayed, abnormal or absent speech
echolalia (repeating words, questions or phrases)
difficulty initiating or sustaining conversations
difficulty understanding non-literal speech
lack of spontaneous pretend play or social imitation
3. Repetitive, restricted or stereotyped behaviour, such as
resistant to changes in routine
stereotyped and repetitive motor mannerisms, such as rocking, spinning, hand or finger flapping or twisting, or complex whole-body movements
intense preoccupations with objects or parts of objects
obsessive, narrow interests
Other features associated with autism:
sensitivity to stimuli (lights, sounds, touch, smell, etc.), or
lack of sensitivity and decreased perception of pain
tendency to focus on details rather that the bigger picture
Usually individuals with autism do not display all of the behaviours described above, but all individuals show some impairment in social interaction and communication, along with repetitive and stereotyped behaviours or interests.
Recognising Asperger’s syndrome
Individuals with Asperger’s syndrome usually have milder symptoms than individuals with autism. Asperger’s syndrome also has a different presentation to autism, even though these individuals struggle with many of the same things, such as communicating with others. For example, while individuals with Asperger’s syndrome are also socially isolated, they are not unaware of the presence of others. In fact, individuals with Asperger’s syndrome often deeply desire friendships. Because they struggle to understand unspoken social rules, however, their social interactions are peculiar and often inappropriate, making it difficult to establish relationships. This is especially true during school-going years, when children with Asperger’s syndrome are often victims of bullying because of their strange behaviour or speech.
Even though speech is not delayed in Asperger’s syndrome, individuals with Asperger’s, like those with autism, struggle to communicate with others. This is because they may struggle to understand another person’s body language or miss out on clues given by tone of voice, so that they find it hard to understand abstract or non-literal speech. Many find eye contact, an important means of conveying information during a conversation, difficult or even painful. They may also fail to understand, or may react inappropriately to, another person’s expression of emotions. Individuals with Asperger’s syndrome may be able to correctly describe emotions and social conventions, but are unable to act upon this knowledge in a natural and spontaneous way during conversation. Because of this lack of spontaneity in social interactions, individuals with Asperger’s syndrome may rely heavily on formal rules of behaviour and social convention. These behaviours may cause individuals with Asperger’s to appear rigid, insensitive or socially naïve. On the other hand, and in contrast to individuals with autism, individuals with Asperger’s syndrome are often hyper-verbal or hyperlexic, and may be very talkative and engage listeners in long conversations about their specific interests.
Individuals with Asperger’s syndrome have average or above-average intelligence, but may struggle academically because of the demands of a classroom. Factors that make it difficult for them to cope include a lack of structure, overwhelming sensory stimuli (such as overhead lights or noise), and complex, abstract instructions.
Poor gross-motor skills (such as struggling to kick a ball or walk on a ledge) are often present in Asperger’s syndrome. A diagnosis of Asperger’s syndrome may also be accompanied by various other diagnoses; including attention deficit and/or hyperactivity disorder because of difficulties in concentrating, anxiety disorder,or depression due to the social isolation experienced by many with Asperger’s syndrome.
Adapted from In-depth Report of Asperger’s Disorder’s Features (2007), PsychCentral