Autism spectrum disorder (ASD) refers to a range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication. Autism affects information processing in the brain by altering how nerve cells and their synapses connect and organize. This affects how a person perceives their environment and their own thoughts and feelings. The onset of autism symptoms occurs early in childhood, usually before age 3. However, autism exists on a spectrum, meaning it affects each individual differently. Some children show signs from birth, while others develop normally for the first few months or years before symptoms start to emerge.
When does autism first appear?
Autism arises early in life, with the vast majority of cases apparent by age 3. According to the CDC, autism can be reliably diagnosed by age 2. Some children show warning signs from birth or before 12 months, while others appear to develop typically at first with symptoms emerging between 12 and 24 months. By age 3, most children with autism will show some behavioral signs and symptoms if appropriate diagnostic tools are used.
Some key points about the onset of autism:
- Symptoms emerge between 12 and 24 months in most cases.
- Autism can be often reliably diagnosed by age 2.
- Most children show some symptoms by age 3.
- Early screening and evaluation is recommended whenever concerns arise.
- Some children show signs from birth, but others appear to develop normally at first.
The earliest signs may be subtle and easy to miss. Parents often look back in hindsight and realize differences were present earlier than they initially realized.
What are the early signs of autism?
Some of the earliest signs and symptoms of autism in babies and toddlers can involve:
Social development:
- Not responding to their name by 12 months
- Avoiding eye contact or not looking at faces
- Not smiling socially or showing other facial expressions
- Not babbling or pointing by 12 months
- Not showing typical back-and-forth gestures like waving or reaching
- Seeming disinterested in other people generally
Communication development:
- Delayed speech development and learning words
- Loss of language or social skills previously acquired
- Repetitive use of words or phrases
- Not responding to their name
- Trouble communicating needs using typical gestures like pointing
Play skills:
- Lack of imaginative or pretend play
- More interest in parts of objects than the whole (like spinning wheels on a toy car)
- Repeating certain behaviors or having specific routines
- Unusual finger or body movements like hand flapping or rocking
- Playing with toys in repetitive ways
Behavioral patterns:
- Excessive tantrums, crying, head banging or aggression
- Withdrawing into their own world
- Unusual reactions to sensory information like noises or textures
- Excessive attachment to certain objects
- Obsessive interests or rituals
No single behavior definitively indicates autism. Progress should be evaluated in context of what’s developmentally appropriate for the child’s age. Early screening creates the best opportunity for early diagnosis and intervention.
How does autism develop in the first year of life?
Autism manifests differently in each child, but we can break down some of the common developmental patterns in the first year:
0-6 months:
Most babies with autism appear to develop typically in the first six months. Possible early signs include:
- Not reacting to loud noises
- Difficulty settling into routines
- Resistance to cuddling
- Limited facial expressions
- Poor eye contact
However, these signs are subtle and variable. Speech delays usually do not emerge until later. At this age, autism is very difficult to diagnose reliably.
6-12 months:
Symptoms become more pronounced in the second half of the first year:
- Lack of back-and-forth gestures like pointing, waving or reaching
- Not responding to their name
- Poor eye contact
- Lack of interest in faces
- Delayed babbling
- Minimal facial expressions
- Preference for solitary play
12-24 months:
This age range is when communication delays become more apparent:
- Very few or no spoken words
- Loss of language previously gained
- Delayed speech understanding
- Limited gestures like pointing to express needs
- Poor response when name is called
- Reduced interest in social interaction
Repetitive behaviors may also emerge, like rocking, spinning or hand flapping. Unusual sensory responses, like oversensitivity to noise, also become more noticeable.
What are the stages of early autism development?
Autism emerges gradually over the early childhood years. We can break it down into three broad stages:
Stage 1: Pre-symptomatic
- Age: Birth to 6 months
- Characteristics: Mostly typical development, few if any apparent symptoms
- Milestones: Normal social engagement, motor control, vision, hearing
- Diagnosis: Too early for clear diagnosis
Stage 2: Emerging symptoms
- Age: 6 to 18 months
- Characteristics: Early social and communication differences emerge, lack of eye contact, limited facial expressions, delay in babbling and gestures
- Milestones: Skills lag in social interaction, speech and language
- Diagnosis: Concerns identifiable but too early for definitive diagnosis
Stage 3: Obvious delays
- Age: 18 to 36 months
- Characteristics: Distinct social and language delays, absence of speech, repetitive behaviors, sensory issues
- Milestones: Regression or plateau of previously acquired skills
- Diagnosis: Clear symptoms allowing for accurate diagnosis by age 2 to 3
Autism is a spectrum disorder with a wide range of individual variation. However, this basic developmental pattern holds true in most cases.
What parents should look for in the first months and years
Many children with autism appear to develop typically as infants. Around 6 to 12 months, key social and communication milestones start getting missed or delayed. Things parents can look for include:
- Lack of typical babbling noises
- Not turning when name is called
- Minimal facial expressions
- Avoiding eye contact
- Trouble communicating through gestures
- Delay in speech and language
- Loss of speech, babbling or gestures
- Repetitive movements like rocking or spinning
- Unusual reactions to sensory stimuli
If any of these raise concern in the first two years, discussing them with the child’s doctor is recommended. Early screening and intervention provide the greatest opportunity to support development.
How early can autism be detected?
Detecting autism as early as possible leads to better outcomes. Here is how early diagnosis evolves:
By 12 months:
- Suspected in some cases, but difficult to diagnose definitively
- Social and communication lags may be identifiable
- Tracking milestones is crucial for detecting delays
By 18 months:
- More clear symptoms allowing tentative diagnosis
- Language delays and unusual behaviors more apparent
- Evaluation by specialist recommended if concerns exist
By 24 months:
- Autism can be diagnosed reliably in most children
- Significant language and social delays noticeable
- Screening should be performed whenever concerns exist
By age 3:
- Autism diagnosis can be made definitively
- Symptoms clearly evident in social interaction, communication, play and behavior
- Intervention should begin as soon as diagnosis is made
The earlier autism is caught, the sooner intervention services can begin to support development. Waiting leads to worse outcomes. Early screening provides the best opportunity for improvement.
What screening and diagnostic tools identify autism?
Several autism screening and diagnostic tools exist for children under 3 years old. These include:
Screening Tools:
- M-CHAT (Modified Checklist for Autism in Toddlers)
- CSBS DP (Communication and Symbolic Behavior Scales)
- SWYC (Screening Tool for Autism in Two-Year-Olds)
- STAT (Screening Tool for Autism in Toddlers & Young Children)
Diagnostic Tools:
- ADOS-2 (Autism Diagnostic Observation Schedule)
- ADI-R (Autism Diagnostic Interview-Revised)
- CARS-2 (Childhood Autism Rating Scale)
- DSM-5 (Diagnostic criteria for ASD)
Using validated screening and diagnostic tools allows for evidence-based identification of autism early in development. Tracking milestones and addressing any concerns is key.
What therapies help autism starting under age 3?
Effective autism therapies initiated before age 3 can greatly improve outcomes. Recommended early interventions include:
- Applied Behavior Analysis (ABA) – Structured teaching of communication, social, motor and cognitive skills
- Speech Therapy – Improve verbal and nonverbal communication abilities
- Occupational Therapy – Help with sensory issues, motor skills and self-care skills
- Physical Therapy – Improve balance, coordination and motor planning
- Developmental Intervention – Target social, emotional, cognitive, motor and adaptive development
Starting intensive therapies before age 3 capitalizes on neuroplasticity to improve autistic children’s long-term functionality and independence. Early intervention is crucial.
Conclusion
The onset of autism occurs early in life, with most children showing clear symptoms by age 2 to 3. Early signs can involve social difficulties, communication delays, speech problems, repetitive behaviors and sensory issues. Autism develops gradually, going from subtle symptoms to more obvious delays in the first few years. The earlier it is detected and treated, the better children’s outlooks become. Screening and therapy before age 3 provide the greatest opportunity to support positive development. Progress monitoring and prompt intervention offer autistic children the best chance at reaching their full potential.