Autism spectrum

The autism spectrum, also called autism spectrum disorders (ASD) or autism spectrum conditions (ASC), with the adjective autistic sometimes replacing the noun autism, is a spectrum of psychological conditions characterized by widespread abnormalities of social interactions and communication as well as restricted interests and repetitive behaviour.

History
Swiss psychologist Eugen Bleuler first used Autism about 100 years ago while defining signs of schizophrenia. Autism comes from the Greek word αὐτός (autós), meaning self. Because the word refers to egocentric thinking, Bleuler defined autism as "autistic withdrawal of the patient to his fantasies, against which any influence from outside becomes an intolerable disturbance." This definition would manifest as characteristics of autism such as obsession with small details, or an inability to stray from a routine. In the United States, researchers first used the word Autism in the 1940s “to describe children with emotional or social problems.” This definition still holds true, as the main characteristics of Autism disorders are difficulties socializing and communicating. In the 1960s, the benefits of early intervention and parent therapy began to gain importance as well. Early on, no link between genetics and autism existed, while now, autism is seen as “one of the most heritable of all psychiatric conditions.” Today, 1 out of every 110 children born is diagnosed with an Autism Spectrum Disorder.

Classification
The three forms of ASD are:
 * 1) Classic autism
 * 2) Asperger syndrome
 * 3) Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS), sometimes called atypical autism.

Classic autism forms the core of the autism spectrum disorders. Asperger syndrome is closest to autism in signs and likely causes; unlike autism, people with Asperger syndrome have no significant delay in language development. PDD-NOS is diagnosed when the criteria are not met for a more specific disorder. Some sources also include Rett syndrome and childhood disintegrative disorder, which share several signs with autism but may have unrelated causes; other sources combine ASD with these two conditions into the pervasive developmental disorders. According to the National Autistic Society of the United Kingdom, pathological demand avoidance syndrome belongs and is increasingly being recognised as belonging to the autistic spectrum.

The terminology of autism can be bewildering. Autism, Asperger syndrome, and PDD-NOS are sometimes called the autistic disorders instead of ASD, whereas autism itself is often called autistic disorder, childhood autism, or infantile autism. Although the older term pervasive developmental disorder and the newer term autism spectrum disorder largely or entirely overlap, the former was intended to describe a specific set of diagnostic labels, whereas the latter refers to a postulated spectrum disorder linking various conditions. ASD, in turn, is a subset of the broader autism phenotype (BAP), which describes individuals who may not have ASD but do have autistic-like traits, such as avoiding eye contact.

Characteristics
The defining characteristics of autism spectrum disorders are qualitative impairments of social communication and interaction, along with restricted and repetitive activities and interests. Individual symptoms occur in the general population and appear not to associate highly, without a sharp line separating pathological severity from common traits. Other aspects of ASD, such as atypical eating, are also common but are not essential for diagnosis; they can affect the individual or the family.

An estimated 0.5% to 10% of individuals with ASD show unusual abilities, ranging from splinter skills such as the memorization of trivia to the extraordinarily rare talents found in autistic savants.

Making and maintaining friendships often proves to be difficult for children with autism. For them, the quality of friendships, not the number of friends, predicts how lonely they are, despite the common belief that they prefer to be alone. Being on the autism spectrum does not keep children from understanding race and gender stereotypes in a society; like normal children they can learn aspects of stereotypical behaviour by observing their parents' actions.

Management
The main goals of treatment are to lessen associated deficits and family distress, and to increase quality of life and functional independence. No single treatment is best and treatment is typically tailored to the child's needs. Intensive, sustained special education programmes and behaviour therapy early in life can help children acquire self-care, social, and job skills. Available approaches include applied behaviour analysis (ABA), developmental models, structured teaching, speech and language therapy, social skills therapy, and occupational therapy. ABA therapy has a strong research base but it maybe limited by diagnostic severity and IQ.

Many popular therapies including auditory integration therapy, GFCF diets, and chelation have repeatedly been shown to be ineffective and are not considered evidence-based practices.

Epidemiology
Most recent reviews tend to estimate a prevalence of 1–2 per 1,000 for autism and close to 6 per 1,000 for ASD; because of inadequate data, these numbers may underestimate ASD's true prevalence. PDD-NOS's prevalence has been estimated at 3.7 per 1,000, Asperger syndrome at roughly 0.6 per 1,000, and childhood disintegrative disorder at 0.02 per 1,000. The number of reported cases of autism increased dramatically in the 1990s and early 2000s. This increase is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness, though as-yet-unidentified environmental risk factors cannot be ruled out, and the available evidence does not rule out the possibility that autism's true prevalence has increased.