Autism spectrum disorder: early identification and management in primary care

'Autism', derived from the Greek word 'autos', or 'self', refers to someone who 'lives in a world of his own'. Hence, autism spectrum disorder (ASD) is a neurodevelopmental condition that affects a person's ability to make sense of the world and relate to other people. It is characterised by persistent deficits in social communication and interaction, as well as restricted, repetitive patterns of behaviour and interests. These manifest during the early developmental period and cause clinically significant impairment of social and occupational function (Box 1). (1) The Diagnostic and Statistical Manual of Mental Disorders (DSM), Fifth Edition, refers to ASD as a single condition with different levels of severity, collectively representing four subtypes that were previously defined in DSM-IV (autistic disorder, Asperger's syndrome, childhood disintegrative disorder and pervasive developmental disorder not otherwise specified). (1) ASD is also associated with psychiatric comorbidities such as anxiety, aggression, attention deficit hyperactivity disorder and obsessivecompulsive disorder. he exact aetiology of ASD is unknown; it is thought to have strong and complex genetic underpinnings with modulation of phenotypic expression by environmental factors. (3) Normal childhood vaccines have been falsely implicated in the causation of ASD, and extensive research has now proven no link between vaccination and ASD. (4) Factors associated with increased risk of ASD include: (5) male gender; family history of sibling or parent with ASD; advanced paternal and maternal age; prematurity (gestational age < 35 weeks) or antenatal infections; antenatal exposure to medications (e.g. valproate and antidepressants); and genetic syndromes such as fragile X syndrome, tuberous sclerosis, Rett syndrome, Down syndrome, muscular dystrophy and neurofibromatosis.