Autism spectrum disorder: early signs, diagnosis and early intervention
What autism is, early signs in toddlers, how it is assessed, why early intervention helps, support available in India, and therapies to avoid.
Also known as: ASD; Asperger Syndrome; Autism; Autistic continuum; Pervasive Developmental Disorder; Pervasive developmental disorder (PDD)
What autism is
Autism spectrum disorder (ASD), or autism, is a lifelong neurodevelopmental condition that affects how a person communicates, relates to others, and experiences the world. It is called a spectrum because it shows up very differently in different people: some autistic people speak fluently and live independently, while others have little speech and need support throughout life.
Autism is not caused by parenting, by too much screen time on its own, or by vaccines — research has firmly shown that the MMR vaccine does not cause autism. It is not a disease to be cured. Autistic people have strengths as well as challenges, and with the right support at the right time, children learn, communicate and participate far better.
Early signs
Signs usually appear in the first two to three years of life. In babies and toddlers, look for:
- Limited eye contact, or few smiles back at familiar people
- Not responding to name by around the first birthday
- Not pointing to show things, or not looking where you point
- Delayed speech, or loss of words or skills they once had
- Little interest in playing with others or in pretend play
- Repetitive movements such as hand-flapping, rocking or spinning
- Lining up toys, intense interest in particular objects, or distress at small changes in routine
- Sensory sensitivities — strong reactions to sounds, textures, lights or food, or seeming not to feel pain
Any loss of speech or social skills at any age needs prompt assessment. In older children and adults, autism may show as difficulty understanding social cues, preferring routines, very focused interests, and finding social situations exhausting. Girls are often diagnosed later because their signs can be less obvious.
Causes and who is at risk
There is no single cause. Genes play a major role, and some environmental factors in pregnancy contribute. Likelihood is higher with:
- An older brother or sister, or a parent, who is autistic
- Certain genetic conditions, such as fragile X syndrome and tuberous sclerosis
- Premature birth or very low birth weight
- Older parental age
How it is diagnosed
Developmental screening at routine visits checks how a child is progressing in speech, play and social skills. Questionnaires such as the M-CHAT (Modified Checklist for Autism in Toddlers) help identify toddlers who need further assessment. Screening is not a diagnosis.
A full diagnostic assessment is done by a developmental paediatrician, child psychiatrist or clinical psychologist, often with a team that includes speech and occupational therapists. It involves a detailed developmental history, observation of the child's communication and play, and standardised tools. A hearing test is always done, because hearing loss can look like autism. The team also looks for related conditions such as intellectual disability, ADHD, epilepsy, sleep problems and anxiety.
Do not wait for a child to 'outgrow' a speech or social delay. If you are worried, ask for an assessment.
Which professional to see
A paediatrician, especially a developmental paediatrician, is usually the first specialist and coordinates care. A psychiatrist, ideally a child psychiatrist, helps with diagnosis and with anxiety, attention or behaviour difficulties. A clinical psychologist helps with assessment and behavioural approaches. Occupational therapists and speech and language therapists are allied-health professionals, not doctors, and are central to day-to-day therapy.
You can find paediatricians in Bengaluru, psychiatrists, clinical psychologists and occupational therapists on The Doctor Index.
In India, autism spectrum disorder is one of the disabilities recognised under the Rights of Persons with Disabilities Act, 2016. An autistic person can apply for a disability certificate and Unique Disability ID (UDID) through the government's UDID portal, which helps with access to schemes and benefits.
Early intervention and support
Early intervention — starting support as soon as concerns are noticed, without waiting for a formal diagnosis — gives the best chance of building communication, social and daily living skills. The brain develops rapidly in the early years, and children learn best through play and everyday routines.
- Parent-mediated intervention — therapists coach parents to build communication and play into daily routines; this is effective and makes therapy part of everyday life
- Speech and language therapy — develops understanding, speech and alternative ways to communicate, such as pictures or devices
- Occupational therapy — helps with sensory differences, motor skills and daily tasks such as dressing and eating
- Behavioural and developmental approaches, delivered by trained therapists, to build skills and reduce behaviours that cause harm
- Educational support in an inclusive or special school with an individualised plan
There are no medicines that treat autism itself. Medicines may be used for related problems, such as severe irritability, sleep difficulty, ADHD, anxiety or epilepsy, under specialist supervision.
Living with autism
Predictable routines, visual schedules, warning before changes and a calm sensory environment help many autistic children. Build on their interests and strengths. Teach safety skills early. As children grow, focus on independence, education and, later, work. Parents and siblings need support too; caring can be demanding, and parent groups and respite help. Autistic adults may benefit from support with work, relationships and mental health.
When it is urgent
Call 112 or 108 for a seizure that does not stop, a serious injury, or a child who has swallowed something harmful. Seek urgent help if an autistic child or adult is harming themselves or others, or for sudden loss of skills, new seizures or a dramatic change in behaviour, which can signal a medical problem such as pain or illness. For thoughts of self-harm in teenagers or adults, call 112 or Tele-MANAS on 14416.
Questions to ask at your appointment
- Is my child's development on track, and what should we watch?
- Should we have a full autism assessment, and who does it?
- Can we start therapy now, before a formal diagnosis?
- Which therapies are recommended for my child, and how often?
- How can I support communication and play at home?
- How do we apply for a disability certificate and UDID, and what support can school give?
Common questions
Questions people ask
- Do vaccines cause autism?
- No. Large studies involving millions of children have shown that vaccines, including the MMR vaccine, do not cause autism. The original study that suggested a link was found to be fraudulent and was withdrawn. Vaccinating your child protects them from serious diseases.
- Can autism be cured?
- No. Autism is a lifelong difference in brain development, not a disease. Be wary of anyone selling a cure. Early intervention, therapy and the right educational support help autistic children develop skills and independence, and many lead fulfilling lives.
- Should I wait to see if my child's speech catches up?
- It is better not to wait. If your toddler is not babbling, pointing, responding to their name or using words when expected, ask for an assessment. Starting support early helps whether or not the child is later diagnosed with autism.
- Is a disability certificate available for autism in India?
- Yes. Autism spectrum disorder is a recognised disability under the Rights of Persons with Disabilities Act, 2016. Families can apply for a disability certificate and Unique Disability ID (UDID) through the government's UDID portal, which can help with access to schemes and educational support.
This condition is usually assessed by a paediatrician. Every profile shows the doctor’s registration and what has been checked.
Paediatricians in Bangalore
A few paediatricians listed on The Doctor Index. They are shown because of their speciality, not a stated interest in Autism Spectrum Disorder; ask the clinic whether the doctor sees it.
Practical reading
All postsSources
- MedlinePlus, US National Library of Medicine — Autism Spectrum Disorder
- World Health Organization — Autism fact sheet
- Press Information Bureau, Government of India — Rights of Persons with Disabilities Bill, 2016 passed by Parliament
- Department of Empowerment of Persons with Disabilities — Unique Disability ID (UDID)
- MedlinePlus, National Library of Medicine — Autism Spectrum Disorder — Public-domain health-topic summary
- MedlinePlus Genetics — Autism spectrum disorder — Public-domain Genetics summary
Autism spectrum disorder: early signs, diagnosis and early intervention is original text by The Doctor Index; the compiled source draft was used for research. Source: MedlinePlus, National Library of Medicine. Orphadata Science: Free access data from Orphanet. © INSERM 1999; July 2026 data, CC BY 4.0. This product uses the Human Phenotype Ontology (hp/releases/2026-09-01). Only sources listed for this article apply. Source material has been selected and arranged; HPO definitions are reproduced without alteration. No source organisation endorses this compilation. Köhler S et al. The Human Phenotype Ontology project: linking molecular biology and disease through phenotype data. Nucleic Acids Research 2014;42(D1):D966–D974. doi:10.1093/nar/gkt1026.
General information, not advice about your situation. Errors can be reported through the corrections process. Reference TDI-C-0251.