History of Autism in Timeline

Autism spectrum disorder (ASD) is a neurodevelopmental condition defined by difficulties in social interaction and communication, alongside repetitive, restricted behaviors and interests. Diagnostic criteria include significant functional impairment caused by these symptoms, which must also be atypical for the individual's age and sociocultural setting. Sensory abnormalities and motor coordination issues are often associated with autism but aren't essential for diagnosis.

1963: British National Autistic Society chose puzzle piece as logo

In 1963, the British National Autistic Society chose a puzzle piece as its logo, which consisted of a green and black puzzle piece with four knobs, with a crying child at its center.

1980: Collaborative work toward a convergence of the ICD and DSM

Since 1980 (when DSM-III was published and ICD-9 was current), there has been collaborative work toward a convergence of the two manuals, including more rigorous biological assessment and a simplification of the classification system.

1994: U.S. special-education autism classification was introduced

In 1994, the U.S. special-education autism classification was introduced.

1994: ICD-10 comes into effect

In 1994, the World Health Organization's International Classification of Diseases, 10th revision (ICD-10) came into effect. This manual is used to codify diagnostic criteria for various diseases, including autism spectrum disorder.

1998: Increase in autism diagnoses began

From 1998 to 2018, autism diagnoses in the UK increased by 787%.

1998: Wakefield's fraudulent study linking MMR vaccine to autism

In 1998, Andrew Wakefield published a fraudulent study suggesting a link between the MMR vaccine and autism. His co-authors have since recanted the claims made in the study, but the initial publication led to significant public concern and distrust of vaccines.

1999: Autism Society designed the puzzle ribbon

In 1999, the Autism Society designed the puzzle ribbon (an awareness ribbon patterned with red, yellow, cyan, and blue puzzle pieces) as a symbol of autism awareness.

2000: ASD rate

In 2000, the rate of children diagnosed with ASD was 1 in 150.

2000: Records of diagnosed ASD began being kept in the US

Since 2000, when records began being kept, the rates for diagnosed ASD have been steadily increasing in the US.

2004: Rainbow infinity symbol designed

In 2004, neurodiversity advocates Amy and Gwen Nelson designed the "rainbow infinity symbol", originally as the logo for their advocacy group Aspies For Freedom, which was later widely adopted as a symbol for the autism spectrum.

2005: Botched chelation therapy death

In 2005, a five-year-old child with autism died due to botched chelation therapy. Chelation is not recommended for autistic people since the associated risks outweigh any potential benefits.

2005: Autistic pride flag created

In 2005, an autistic pride flag was created by Aspies For Freedom for the first Autistic Pride Day, featuring a rainbow infinity symbol on a white background.

2005: Studies published from 2005 to 2016 that concluded that associations between autism spectrum disorder (ASD) and screen time was inconclusive

In September 2018, the Review Journal of Autism and Developmental Disorders published a systematic review of 47 studies published from 2005 to 2016 that concluded that associations between autism spectrum disorder (ASD) and screen time was inconclusive.

2006: ASD rate

In 2006, the rate of children diagnosed with ASD was 1 in 110.

2007: Autism Speaks launched Light It Up Blue campaign

In 2007, Autism Speaks launched the "Light It Up Blue" awareness campaign. In 2018, Julian Morgan wrote the article "Light It Up Gold", a response to the "Light It Up Blue" awareness campaign.

2011: ASD rates

Between 2011 and 2014, ASD rate was 1.25%.

2011: Solitary Forager Hypothesis proposed

In 2011, a paper in Evolutionary Psychology proposed that autistic traits, including increased spatial intelligence, concentration and memory, could have been naturally selected to enable self-sufficient foraging in a more solitary environment. This is called the 'Solitary Forager Hypothesis'.

2011: Autism Acceptance Month celebrated

Since 2011, the Autistic Self Advocacy Network has celebrated April as Autism Acceptance Month.

2012: WHO estimates about 1 in 100 children had autism

From 2012 to 2021, the World Health Organization estimates about 1 in 100 children had autism with a trend of increasing prevalence over time. However, the study's 1% figure may reflect an underestimate of prevalence in low- and middle-income countries.

2012: WHO estimates of autism prevalence

In 2012, The World Health Organization estimated that about 1 in 100 children had autism, which was the average estimate in studies between 2012 and 2021. The WHO also identified a trend of increasing prevalence over time.

2012: The "double empathy problem" theory

In 2012, the "double empathy problem" theory argues that there is a lack of mutual understanding and empathy between both non-autistic persons and autistic individuals.

2012: NHS estimated the overall prevalence of autism in the UK

In 2012, the NHS estimated that the overall prevalence of autism among adults aged 18 years and over in the UK was 1.1%.

May 2013: Release of the DSM-5

In May 2013, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) was released. It was the first to define ASD as a single diagnosis, encompassing previous diagnoses and adopting a dimensional approach. The DSM-5 includes a framework that differentiates each person by dimensions of symptom severity and associated features.

2013: Social function and communication deficits considered two separate symptom domains until 2013

According to the medical model, autistic people experience social communications impairments. Until 2013, deficits in social function and communication were considered two separate symptom domains. The current social communication domain criteria for autism diagnosis require people to have deficits across three social skills: social-emotional reciprocity, nonverbal communication, and developing and sustaining relationships.

2013: DSM-5 diagnostic manual adopted

In 2013, before the DSM-5 was adopted, ASD was found under the diagnostic category pervasive developmental disorder. The DSM-5 took a spectrum approach and is more restrictive, meaning fewer people qualify for diagnosis.

2013: Publication of DSM-5

In 2013, the American Psychiatric Association published the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition). This manual is used to codify diagnostic criteria for various mental disorders, including autism spectrum disorder.

2014: ASD rates twice as high as 2011-2014 period

In 2014, ASD rates were found to be twice as high (2.47%) compared to the time period between 2011 and 2014 (1.25%).

2014: Meta-analysis confirms no link between vaccines and autism

In 2014, a meta-analysis examined ten major studies on autism and vaccines involving 1.25 million children worldwide. The analysis concluded that neither the vaccine preservative thimerosal, nor the MMR vaccine, lead to the development of ASDs.

2014: ASD rate

In 2014, the rate of children diagnosed with ASD was 1 in 59.

2014: Study of late diagnosed autistic adults

In a 2014 study of late diagnosed autistic adults, 66% had experienced suicidal ideation and 35% had a suicide plan or had made a suicide attempt.

August 2015: Identification of autistic digital communities

In August 2015, NeuroTribes identified autistic digital communities such as Autism Network International, Wrong Planet, and the Autism List mailing list at St. John's University (New York City).

October 2015: AAP proposes new evidence-based recommendations for early interventions in ASD

In October 2015, the American Academy of Pediatrics (AAP) proposed new evidence-based recommendations for early interventions in ASD for children under 3, emphasizing developmental and behavioral methods, parental support, and focus on core and associated symptoms.

2015: Autistic pride design by Joseph Redford

In 2015, Joseph Redford created an autistic pride design featuring a rainbow infinity symbol, a green background for being true to one's nature, and a purple background for neurodiversity. The design was featured in the People's History Museum in 2023.

2015: CDC estimated that around 40% of autistic children do not speak at all

In 2015, the CDC estimated that around 40% of autistic children do not speak at all.

2016: Asperger syndrome as an alternative prosocial adaptive strategy

A 2016 paper examines Asperger syndrome as 'an alternative prosocial adaptive strategy' that may have developed as a result of the emergence of 'collaborative morality' in the context of small-scale hunter-gathering.

2016: ASD rates remain constant

In 2016, ASD rates were constant compared to 2014 but twice the rate compared to the time period between 2011 and 2014 (1.25 vs 2.47%).

2016: Data Collected for ASD rate

In 2016, data was collected which showed approximately 1 in 54 children in the United States (1 in 34 boys, and 1 in 144 girls) is diagnosed with an autism spectrum disorder (ASD).

2016: Studies published from 2005 to 2016 that concluded that associations between autism spectrum disorder (ASD) and screen time was inconclusive

June 2018: Release of the ICD-11

In June 2018, the World Health Organization's International Classification of Diseases (11th revision), ICD-11, was released. It describes ASD.

September 2018: Systematic review of studies concludes associations between ASD and screen time was inconclusive

In September 2018, the Review Journal of Autism and Developmental Disorders published a systematic review of studies published from 2005 to 2016 that concluded that associations between autism spectrum disorder (ASD) and screen time was inconclusive.

2018: Heritability of ASD

As of 2018, research suggested that between 74% and 93% of ASD risk is heritable. It was also observed that if parents have one autistic child, there is a 2% to 8% chance of having another autistic child. For identical twins, there is a 36% to 95% chance of both being affected, while fraternal twins have up to a 31% chance.

2018: Increase in autism diagnoses

From 1998 to 2018, the autism diagnoses increased by 787% in the UK.

2018: Light It Up Gold article written

In 2018, Julian Morgan wrote the article "Light It Up Gold", a response to the "Light It Up Blue" awareness campaign.

2018: Meta-analysis on ABA teaching approaches

In 2018, a Cochrane meta-analysis database concluded that some recent research is beginning to suggest that because of the heterology of ASD, there are two different ABA teaching approaches to acquiring spoken language: children with higher receptive language skills respond to 2.5 to 20 hours per week of the naturalistic approach, whereas children with lower receptive language skills require 25 hours per week of discrete trial training—the structured and intensive form of ABA.

2018: Review of gluten- and casein-free diet as treatment

In 2018, a review of literature showed there is no good evidence to recommend a gluten- and casein-free diet as a standard treatment for autism. However, it concluded that the diet may be a therapeutic option for specific groups of children with autism, such as those with known food intolerances or allergies, or with food intolerance markers.

2018: Genetic risk factors in ASD

In 2018, understanding of genetic risk factors in ASD shifted to focus on a large number of variants, some common with small effects, and others rare with large effects. The most commonly disrupted gene with large effect rare variants was found to be CHD8, present in less than 0.5% of autistic individuals.

May 2019: Children and adolescents with ASD are exposed to more screen time

In May 2019, the Journal of Developmental and Behavioral Pediatrics published a systematic review of studies that found that children and adolescents with ASD are exposed to more screen time than typically developing peers and that the exposure starts at a younger age.

2019: Autistic people are four times more likely to have depression than non-autistic people

A 2019 meta-analysis found autistic people to be four times more likely to have depression than non-autistic people, with approximately 40% of autistic adults having depression.

2019: Canadian meta-analysis

In 2019, a Canadian meta-analysis confirmed that the profiles of autistic people were becoming less and less different from the profiles of the general population.

2019: Research recorded similar social cognitive performances in autistic and non-autistic adults

Recent (2019) research recorded similar social cognitive performances in autistic and non-autistic adults. Both rated autistic individuals less favorably than non-autistic individuals. Autistic individuals showed more interest in engaging with autistic people than non-autistic people did, and learning of a person's ASD diagnosis did not influence their interest level.

2020: Systematic review on adults with autism

In 2020, a systematic review on adults with autism provided evidence that mindfulness-based interventions may decrease stress, anxiety, ruminating thoughts, anger, and aggression and improve mental health.

2020: Non-autistic people struggle to identify autistic mental states

In 2020, researcher Catherine Crompton wrote that non-autistic people "struggle to identify autistic mental states, identify autistic facial expressions, overestimate autistic egocentricity, and are less willing to socially interact with autistic people.

2020: CDC reports autism spectrum disorder rates

In 2020, the Centers for Disease Control's Autism and Developmental Disabilities Monitoring (ADDM) Network reported that approximately 1 in 54 children in the United States is diagnosed with an autism spectrum disorder (ASD), based on data collected in 2016.

April 2021: Children, adolescents, and adults with ASD are at greater risk of video game addiction

In April 2021, Research in Autism Spectrum Disorders published a systematic review of studies of video game addiction in ASD subjects that found that children, adolescents, and adults with ASD are at greater risk of video game addiction than those without ASD.

2021: Increased estimates of autism prevalence

By 2021, the World Health Organization estimated about 1 in 100 children had autism between 2012 and 2021. The increasing prevalence has contributed to the myth perpetuated by anti-vaccine activists that autism is caused by vaccines.

2021: WHO estimates about 1 in 100 children had autism

2021: Autism Acceptance Day urged by Autism Society of America

In 2021, the Autism Society of America urged organizations to retitle Autism Awareness Day as Autism Acceptance Day, to focus on "more fully integrating those 1 in 54 Americans living with autism into our social fabric".

January 2022: ICD-11 comes into full effect

As of January 2022, the World Health Organization's International Classification of Diseases (11th revision), ICD-11, came into full effect. It describes ASD.

March 2022: Majority of studies found positive associations between ASD, problematic internet use, and gaming disorder

In March 2022, the Review Journal of Autism and Developmental Disorders published a systematic review of studies investigating associations between ASD, problematic internet use, and gaming disorder where the majority of the studies found positive associations between the disorders.

2022: Updated Cochrane review on music therapy and research on hyperbaric treatments and pet therapy

An updated Cochrane review in 2022 found evidence that music therapy likely improves social interactions, verbal communication, and nonverbal communication skills. Also in 2022, there has been early research on hyperbaric treatments and studies on pet therapy that have shown positive effects for autistic people.

2022: Review study suggests link between early exposure to aluminium adjuvants in vaccines and autism

In 2022, a review study suggests a link between early exposure to aluminium adjuvants in vaccines and autism.

2022: Release of the DSM-5-TR

In 2022, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR) was released.

2022: ICD-11 comes into effect

In 2022, the World Health Organization's International Classification of Diseases, 11th revision (ICD-11) came into effect and is now being implemented by healthcare systems across the world. This manual is used to codify diagnostic criteria for various diseases, including autism spectrum disorder.

2023: Growing consensus that ASD criteria are ineffective descriptors of autism as a whole

As of 2023, empirical and theoretical research is leading to a growing consensus among researchers that the established ASD criteria are ineffective descriptors of autism as a whole. Alternative research approaches must be encouraged, such as going back to autism prototypes, exploring new causal models of autism, or developing transdiagnostic endophenotypes.

2023: The Suicidal Behaviours Questionnaire–Autism Spectrum Conditions (SBQ-ASC) is the only test validated for autistic people

As of 2023, the Suicidal Behaviours Questionnaire–Autism Spectrum Conditions (SBQ-ASC) is the only test validated for autistic people.

2023: Multi-site randomized control trial study of participants shows similar findings

In 2023, A 2023 multi-site randomized control trial study of 164 participants showed similar findings to the Cochrane meta-analysis on ABA teaching approaches.

2023: People's History Museum featured autistic pride design

In 2023, the People's History Museum featured a 2015 autistic pride design by Joseph Redford, featuring a rainbow infinity symbol, a green background for being true to one's nature, and a purple background for neurodiversity.

2024: ICD-11 CDDR diagnostic manual adopted

In 2024, before the ICD-11 CDDR was adopted, ASD was found under the diagnostic category pervasive developmental disorder. The ICD-11 CDDR took a spectrum approach and is more restrictive, meaning fewer people qualify for diagnosis.