What is autism spectrum disorder?

Autism spectrum disorder (ASD) is a neurodevelopmental condition characterised by differences in social communication and interaction, and restricted or repetitive patterns of behaviour and interests. It is a spectrum — ranging from individuals who may be non-speaking and require intensive daily support, to those with exceptional abilities in specific domains who may need support only in specific social or sensory situations. ASD affects approximately 1 in 100 children globally and is lifelong.

ASD has strong genetic underpinnings — approximately 64-91% heritability in twin studies. Causes include: rare de novo (new, not inherited) mutations in genes like SHANK3, NRXN1, CHD8 and hundreds of others (each contributing to a small percentage of cases); common genetic variants (each with small individual effect); and complex gene-environment interactions. Risk factors include advanced parental age, prenatal valproate exposure, and extreme prematurity. There is NO causal relationship between vaccines (MMR or any other) and autism — this has been extensively studied across millions of children globally.

Does the MMR vaccine cause autism?

No. The claim that the MMR vaccine causes autism originated from a 1998 Lancet paper (Wakefield et al.) that was subsequently found to involve research fraud and data fabrication — the paper was retracted in 2010, and Wakefield lost his medical licence. Numerous large, rigorous studies involving millions of children across multiple countries have consistently found no link between MMR vaccination and autism. The original paper's false claim caused a measles resurgence in multiple countries as vaccination rates fell — causing real harm. Vaccine safety monitoring continues, and no causal link to autism has been found.

What are the early signs of autism?

In infancy and toddlerhood: not responding to name by 12 months; no babbling or pointing by 12 months; no single words by 16 months; no 2-word phrases by 24 months; any regression in language or social skills at any age (red flag requiring immediate evaluation); limited eye contact; little interest in other children; unusual reactions to sensory stimuli (highly distressed by some sounds/textures, unresponsive to pain); lining up objects or repetitive play; insistence on rigid routines.

What supports are available for autistic people?

Evidence-based interventions: early intensive behavioural intervention (EIBI/ABA) — most evidence for improving communication and adaptive skills in young children; speech and language therapy; occupational therapy (sensory processing, daily living skills); social skills groups; and augmentative and alternative communication (AAC) for non-speaking autistic individuals. Education supports: inclusive education with appropriate accommodations; specialist autism provisions. Mental health support: high rates of co-morbid anxiety, depression and ADHD require specific intervention. Importantly, support should be aimed at wellbeing and functional independence, respecting autistic identity.

What is the gender gap in autism diagnosis?

Autism is diagnosed approximately 4 times more often in males than females — but substantial evidence suggests females are significantly underdiagnosed. This partly reflects a "female autism phenotype" — autistic girls and women may show differences in how they present: stronger camouflaging or masking (learning to imitate social behaviour to fit in); greater interest in social situations despite difficulties; and presentations that better match DSM criteria originally developed on male populations. Misdiagnosis of autistic females with anxiety, borderline personality disorder or eating disorders is common. Revised diagnostic tools for females are improving identification.

What is masking or camouflaging?

Masking (or camouflaging) refers to autistic individuals — particularly women and adolescents — consciously or unconsciously suppressing autistic behaviours and learning to perform neurotypical social scripts to fit in. While masking can enable social participation, it is profoundly exhausting (autistic burnout) and associated with significantly higher rates of anxiety, depression and suicidal ideation. Recognition of masking is important for diagnosis (many autistic women receive diagnoses only in adulthood after burnout) and for supporting autistic wellbeing.

What is autistic burnout?

Autistic burnout is a state of extreme exhaustion — physical, mental and social — resulting from sustained masking, navigating a neurotypically-designed world, and accumulated sensory and social overload. It manifests as: profound loss of executive function and daily living skills; withdrawal; increased sensory sensitivities; difficulty communicating; and depression. It is a well-recognised phenomenon in the autistic community, increasingly studied by researchers. Rest, reduced demands and accommodation of autistic needs are the primary recovery strategies.

How does GMJ News cover autism?

GMJ News covers WHO ASD data, neurodiversity framework, early identification and intervention, vaccine safety (refuting autism link), female autism presentation, and access to services globally. Autism is directly relevant to PHIG's child health and mental health priorities and to the Georgian Medical Journal's neurodevelopmental coverage.

Home › Topics › Autism Spectrum Disorder

Autism Spectrum Disorder

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Autism spectrum disorder (ASD) encompasses a range of neurodevelopmental conditions characterised by differences in social communication, interaction, and patterns of behaviour, interests and activities — affecting an estimated 1 in 100 children globally (approximately 75 million people of all ages), with prevalence rising as diagnostic awareness and criteria improve (WHO). ASD is a spectrum — ranging from non-speaking individuals requiring intensive support to highly capable individuals with subtle differences in social interaction. The neurodiversity framework — recognising autism as a natural variation in human neurology rather than a disorder requiring cure — is reshaping care towards support, inclusion and accommodation rather than normalisation.

Key messages

1 in 100 children globally

Autism spectrum disorder (ASD) affects an estimated 1 in 100 children globally — approximately 75 million people of all ages — though rates vary significantly by methodology; US CDC data suggests approximately 1 in 36 American children (2020) with improved diagnostic detection (WHO).

A spectrum — not a single condition

ASD encompasses a wide range of presentations — from non-speaking individuals requiring intensive support for daily life, to highly capable individuals with subtle differences in social communication and narrow interests. No two autistic people are identical.

Neurodiversity framework

The neurodiversity movement — increasingly influential in research, clinical practice and policy — reframes autism as a natural human variation rather than a disorder to be "cured," emphasising support, accommodation and societal adaptation rather than normalisation.

Early identification improves outcomes

Early identification (before age 2-3 years) allows early intervention — behavioural therapies, speech and language therapy, occupational therapy — that substantially improves communication, social skills and adaptive functioning. Developmental surveillance at every paediatric visit is recommended.

No single cause

ASD has strong genetic underpinnings (approximately 64-91% heritability in twin studies) but no single cause. Hundreds of rare gene mutations and de novo variants contribute; common genetic variants add smaller risks. There is NO causal link between vaccines and autism — extensively studied and refuted.

Substantial unmet support needs

Most autistic people worldwide have no access to diagnosis, support services, education accommodations or mental health care. In LMICs, autism is rarely recognised or diagnosed. Stigma, social exclusion and abuse are major concerns.

Key statistics

1 in 100

children with ASD globally (WHO estimate)

WHO

~75M

people of all ages with ASD globally

WHO

1 in 36

US children (2020 CDC — reflects diagnostic improvement)

CDC

4:1

male to female ratio (though females underdiagnosed)

WHO/research

64-91%

heritability in twin studies

Research

causal link between vaccines and autism (consensus)

WHO/CDC

Autism diagnosis rates per 1,000 children in selected countries — WHO/national data

Source: Rates reflect diagnostic infrastructure and awareness — not necessarily true prevalence differences.

Glossary of key terms

Autism spectrum disorder (ASD)
WHO/ICD-11/DSM-5A neurodevelopmental condition characterised by: persistent differences in social communication and interaction (difficulty with reciprocal conversation, understanding social cues, developing relationships); and restricted, repetitive patterns of behaviour, interests or activities (insistence on sameness, stereotyped movements, narrow intense interests, sensory sensitivities). Onset in early childhood (typically evident by age 2-3).

Neurodiversity
Autistic community/researchA framework recognising autism (and ADHD, dyslexia, dyscalculia and other neurological variations) as natural variations in human brain structure and function — not disorders to be pathologised or cured, but differences that society should accommodate. Emphasises autistic strengths and the need for structural changes rather than individual "fixing."

Applied behaviour analysis (ABA)
WHO/researchA behavioural therapy for autism based on operant conditioning principles — widely used and with evidence for improving communication and adaptive skills in young autistic children. Controversial in the autistic community — early intensive ABA was criticised for focusing on normalisation rather than wellbeing. Modern evidence-based ABA focuses on functional skills and child-led interaction.

DSM-5 and ICD-11 ASD criteria
APA/WHOBoth require: (1) persistent differences in social communication and interaction across multiple contexts; (2) restricted, repetitive behaviours/interests; and (3) symptoms present since early childhood. ICD-11 (2022) added "autism spectrum disorder" as the unified category, dropping Asperger syndrome as a separate diagnosis.

Asperger syndrome
History/WHOA former diagnostic category (ICD-10, DSM-IV) for autistic individuals without intellectual disability or clinically significant language delay. Now subsumed within ASD in DSM-5 and ICD-11. Many people who received an Asperger diagnosis continue to identify with this term.

Sensory sensitivities
WHO/DSM-5Hyper- or hypo-reactivity to sensory input (light, sound, touch, smell, taste, proprioception) — now formally recognised in DSM-5 diagnostic criteria for ASD. Sensory sensitivities significantly affect daily functioning — from food selectivity to inability to tolerate specific sounds or fabrics.