Autism Spectrum Disorder (ASD) describe a range of complex neurological conditions that affect an individual's social, communication, and motor skills. It affects as many as one in 68 children, a figure that could still be rising.
Once labelled autism, criteria for its diagnosis was broadened in 2013 for the Diagnostic and Statistical Manual of Mental Disorders' fifth edition to create an umbrella term describing a range of severities and experiences.
It now includes what was referred to as Asperger's Syndrome, though debate continues on whether these conditions should continue to be so closely associated.
Diagnosis is based on persistent deficits in social interactions, such as reciprocating emotions or an absence of interest in friends, repetitive movements or speech, and extreme or unusual reactions to stimuli.
The spectrum also includes intellectual impairments and potential impact on language and communication, depending on the individual characteristics.
What causes ASD?
Thanks in part to the sheer complexity of the condition and the diverse neurological pathways involved, there is no single cause responsible for all of ASD's characteristics. Differences in brain structure and functional connectivity seem to play a key role in some symptoms.
In spite of past speculation that the risk of autism is linked with vaccines, repeated studies have consistently found no relationship.
There is currently no prospect of a 'cure' for autism, but different forms of therapeutic assistance – including pharmaceuticals – could one day work together to help offset some of autism's more severe challenges.