top of page


Autism is a neuro-developmental disorder that becomes evident before the age of three. Autism is characterised by marked impairment in social interaction and communication.

There is a broad spectrum of severity in the disorder and milder forms can sometimes be termed Asperger's syndrome. Persons with autism spectrum disorders commonly have very restricted and repetitive behaviours and can become fixated on certain objects or activities.


What is autism?

Autism is a childhood-onset condition that is characterised by severe impairments in social interaction, language, communication and behaviour.


Autism is a neurodevelopmental condition, which means that it impacts upon the development of the brain. Although it is usually diagnosed in early childhood (around 3-5 years), autism is a life-long condition. The number of people being diagnosed with autism appears to be increasing, and current estimates suggest that between 1 and 2 people in 1000 are affected. There are around 6-8 times more males with autism than females.


There are no established medical treatments that target the core symptoms of autism, but interventions are provided by a number of health professionals, including psychiatrists, psychologists, speech therapists, occupational therapists and special educators.




There are three main features of autism, which together are often referred to as the 'core triad of impairments'. These are described below.

Social relating

Autism involves reduced or abnormal social and emotional behaviours (e.g., eye contact, gesturing) and a failure to seek shared experiences with other people. There is often a lack of enjoyment or interest in social interactions. People with autism appear to have a reduced capacity for understanding what other people are thinking and feeling, and this may underlie many of their social symptoms.

Language and communication

People with autism have significant delays in the acquisition of spoken language, and some people with autism fail to develop speech altogether. Additional language abnormalities include repetitive or idiosyncratic speech and difficulties in engaging in conversation.

Stereotyped/repetitive behaviours

People with autism often have special interests to which they devote a great deal of their time and energy. This can include simple repetitive motor behaviours (e.g., hand flapping) or preoccupations with a particular subject matter (e.g., train timetables). People with autism also typically prefer to do things a particular way, and can become upset or distressed if a routine is broken.


There are also a number of associated features of autism; these are commonly present, and are therefore thought to be related to autism, but are not necessary for a diagnosis to be made. These include intellectual disability (which affects 50-80% of people with autism), motor and physical coordination impairments, sensory impairments, and epilepsy (which is more common when intellectual disability is also present). People with autism are also more likely to experience depression and anxiety.



The cause of autism is not clear, but we do know that it is not due to bad parenting or the effects of immunisation. Recent research suggests that genetic factors do appear to be involved (with twin studies demonstrating heritability rates as high as 90%), but we are only in the early stages of understanding the genetics of autism. A single genetic factor is unlikely to explain all (or perhaps any) instances of autism. While environmental factors have been investigated (e.g., mercury), again there is no conclusive evidence and further research is needed.


Studies of the brain have revealed a number of factors that are associated with autism. This includes reduced activity of certain chemical messengers, enlarged overall brain size (particularly in early childhood), and abnormalities in the structure and function of specific brain cells. Brain imaging studies have indicated abnormal activity levels in specific parts of the brain, such as those responsible for social understanding and processing emotion. More recent brain research suggests that autism may involve excellent short-range communication between brain cells, but relatively poor long-range communication (which is crucial for processing social information).


None of these brain-related changes, however, are present in all people with autism, and at this stage they cannot be used to provide a diagnosis of autism. 

Related Conditions

There are several neurodevelopmental conditions that seem to be related to autism in that they present with very similar symptoms. Together with autism these conditions are often referred to under the label 'autism spectrum disorders' (ASD). Perhaps the most well known of these is Asperger’s syndrome, which is similar to autism in that it involves impairments in social relating and stereotyped/repetitive behaviours. Unlike autism, however, there is no language delay (although there may be communication impairments). In addition, intellectual disability is not present in Asperger’s syndrome, with IQ generally in the above or above average range. The prevalence of ASD also appears to be increasing, and it has been suggested that as many as 1 in 150 children will be diagnosed with an ASD.

Treatments for Autism

There are currently no established medical treatments that target the core symptoms of autism. Nonetheless, medications are sometimes used for associated features including depression, anxiety and behavioural problems.


Psychological and behavioural interventions are the most common treatments for autism, but the needs of individuals with autism and related disorders vary greatly. These interventions use a range of techniques for developing social abilities, coping strategies and general living skills, but will depend on the needs of the individual. Interventions often also target problematic behaviours and attempt to replace them with more appropriate and prosocial behaviours.

Many interventions for autism are aimed at children, and provided in a classroom setting. There are now a number of specialist schools that cater solely for children diagnosed with autism.


Unfortunately, many interventions for autism, while potentially useful, have not been subjected to rigorous scientific evaluation. We therefore do not know about their true effectiveness.


From a biomedical perspective, researchers are currently investigating a range of new medical treatments for autism. This includes diet modification, hormonal treatments (e.g., oxytocin), and non-invasive brain stimulation (e.g., transcranial magnetic stimulation). The next decade should see some exciting advances in the treatment of autism, both for children and adults.

bottom of page