AUTISM SPECTRUM DISORDER (ASD) is a neurological disorder that severely impairs development of a person’s ability to communicate, interact with other people, and the presence of stereotyped behaviors, interests and activities. Individuals with autism will vary in the number of symptoms they present, the severity of those symptoms, the degree of cognitive impairment they will experience, and the number and type of associated medical problems they will have. Because different people with autism can have very different features or symptoms, health care providers think of autism as a “spectrum” disorder – a group of disorders with a range of similar features. Based on their specific strengths and weaknesses, people with ASD may have mild symptoms or more serious symptoms, but they all have ASD.

Source: Autism through the Lifespan: the Eden Model

WHAT CAUSES AUTISM?

Scientists don’t know exactly what causes autism at this time. Much evidence supports the idea that genetic factors – that is genes, their functions and their interactions – are one of the main underlying causes of ASDs. Research has also shown that environmental factors, such as viruses, may also play role in causing autism. While some researchers are examining genes and environmental factors, other researchers are looking at possible neurological, infectious, metabolic, and immunologic factors that may be involved in autism.