Autism Spectrum Disorder (ASD)

Autism Spectrum Disorder (ASD) is a complex neurodevelopment disorder, characterised by social impairments, communication difficulties, and restricted, repetitive, and stereotyped patterns of behaviour. 

Prior to reclassification through the DSM-5 in 2015, classical ASD was considered the most severe form of Autism, while other conditions along the spectrum considered milder included; Asperger Syndrome, Childhood Disintegrative Disorder and Pervasive Developmental Disorder not otherwise specified (usually referred to as PDD-NOS).  Although ASD varies significantly in character and severity, it occurs in all ethnic and socioeconomic groups and affects every age group.  Experts estimate that six children out of every 1,000 will have an ASD.  Males are four times more likely to have an ASD than females. 

Scientists aren’t certain about what causes ASD, but it’s likely that both genetics and environment play a role.  Researchers have identified a number of genes associated with the disorder.  Studies of people with ASD have found irregularities in several regions of the brain.  Other studies suggest that people with ASD have abnormal levels of serotonin or other neurotransmitters in the brain.  These abnormalities suggest that ASD could result from the disruption of normal brain development early in fetal development caused by defects in genes that control brain growth and that regulate how brain cells communicate with each other, possibly due to the influence of environmental factors on gene function.  While these findings are intriguing, they are preliminary and require further study.  The theory that parental practices are responsible for ASD has long been disproved. 

Twin and family studies strongly suggest that some people have a genetic predisposition to Autism.  Identical twin studies show that if one twin is affected, there is up to a 90 percent chance the other twin will be affected.  There are a number of studies in progress to determine the specific genetic factors associated with the development of ASD.  In families with one child with ASD, the risk of having a second child with the disorder is approximately 5 percent, or one in 20.  This is greater than the risk for the general population.  Researchers are looking for clues about which genes contribute to this increased susceptibility.  In some cases, parents and other relatives of a child with ASD show mild impairments in social and communicative skills or engage in repetitive behaviours.  Evidence also suggests that some emotional disorders, such as bipolar disorder, occur more frequently than average in the families of people with ASD. 

Some issues to consider regarding how ASD affects children:   

1. Symptoms must be present in the early developmental period 
2. Symptoms cause clinically significant impairment in social, occupational, or other important areas of current functioning 
3. These disturbances are not better explained by intellectual disability (intellectual developmental disorder) or global developmental delay 

Severity levels for Autism Spectrum Disorder 

• Level 3 – Requiring very substantial support (severe) 
• Level 2 – Requiring substantial support (moderate) 
• Level 1 – Requiring support (mild) 

The hallmark feature of ASD is impaired social interaction.  As early as infancy, a baby with ASD may be unresponsive to people or focus intently on one item to the exclusion of others for long periods of time.  A child with ASD may appear to develop normally and then withdraw and become indifferent to social engagement. 

Children with ASD may fail to respond to their names and often avoid eye contact with other people.  They have difficulty interpreting what others are thinking or feeling because they can’t understand social cues, such as tone of voice or facial expressions, and don’t watch other people’s faces for clues about appropriate behaviour. They lack empathy. 

Many children with ASD engage in repetitive movements such as rocking and twirling, or in self-abusive behaviour such as biting or head-banging.  They also tend to start speaking later than other children and may refer to themselves by name instead of “I” or “me.”  Children with ASD don’t know how to play interactively with other children.  Some speak in a sing-song voice about a narrow range of favourite topics, with little regard for the interests of the person to whom they are speaking. 

Autism Spectrum Disorder Diagnostic Criteria:

1. Persistent deficits in social communication and social interaction across multiple contexts
   1. Deficits in social-emotional reciprocity 
   2. Deficits in nonverbal communicative behaviours used for social interaction 
   3. Deficits in developing, maintaining, and understanding relationships 
2. Restricted, repetitive patterns of behaviour, interests, or activities 
3. Stereotyped or repetitive motor movements, use of objects, or speech 
4. Insistence on sameness, inflexible adherence to routines, or ritualised patterns 
5. Highly restricted, fixated interests that are abnormal in intensity or focus 
6. Hyper- or hypo reactivity to sensory input or unusual interests in sensory aspects of the environment 

ASD varies widely in severity and symptoms and may go unrecognised, especially in mildly affected children or when it is masked by more debilitating handicaps. 

Very early indicators that require evaluation by an expert include: 

• No babbling or pointing by age 1 
• No single words by 16 months or two-word phrases by age two 
• No response to name 
• Loss of language or social skills 
• Poor eye contact 
• Excessive lining up of toys or objects 
• No smiling or social responsiveness

Later indicators include: 

• Impaired ability to make friends with peers 
• Impaired ability to initiate or sustain a conversation with others 
• Absence or impairment of imaginative and social play 
• Stereotyped, repetitive, or unusual use of language 
• Restricted patterns of interest that are abnormal in intensity or focus 
• Preoccupation with certain objects or subjects 
• Inflexible adherence to specific routines or rituals

For many children, symptoms improve with treatment and with age. Children whose language skills regress early in life—before the age of three —appear to have a higher-than-normal risk of developing epilepsy or seizure-like brain activity.  During adolescence, some children with ASD may become depressed or experience behavioural problems, and their treatment may need some modification as they transition to adulthood.  People with an ASD usually continue to need services and supports as they get older, but many are able to work successfully and live independently or within a supportive environment.