What are the symptoms of autism in a child?

Symptoms of Autism in Children

Children with autism spectrum disorder display two core symptom domains: deficits in social communication/interaction and restricted, repetitive behaviors or interests, with early signs typically emerging between 6-24 months of age. 1, 2

Core Social Communication Deficits

The social communication impairments are often the most recognizable features:

• Poor or absent eye contact is a hallmark feature, particularly noticeable in preschool-aged children and often one of the first concerns parents raise 3, 1, 4
• Failure to respond to name when called by 12 months is highly suggestive of developmental abnormality and frequently leads parents to worry about hearing loss 3, 1, 5
• Marked lack of interest in other people, in stark contrast to the profound social interest of typically developing infants 1
• Impaired peer relationships with lack of interest in playing with other children 3, 1
• Absent or limited use of gestures in communication, particularly not pointing to show interest or share attention at 20-42 months 1, 2
• Lack of imaginative or make-believe play that would be developmentally appropriate 1, 6
• Impaired nonverbal behaviors such as facial expressions and body postures to regulate social interaction, particularly evident from 38-61 months 3

Communication and Language Abnormalities

Language development shows characteristic patterns:

• Delayed or total lack of spoken language with no attempt to compensate through alternative means like gestures 1, 6
• Language regression, where a child speaks and then stops, is less common but significant 1, 4
• Echolalia, the immediate or delayed repetition of words or phrases 1
• Pronoun reversal, such as saying "you" instead of "I" 1
• Stereotyped, repetitive, or idiosyncratic language patterns 1
• Concrete, literal interpretation of language 1
• One-sided, pedantic speech in higher-functioning individuals, often focused on circumscribed interests 1

Restricted, Repetitive Behaviors and Interests

These behaviors are the second core diagnostic domain:

• Stereotyped motor mannerisms such as hand flapping, finger mannerisms, or body rocking 3, 1, 4
• Extreme distress with changes in routine or environment, with marked resistance to transitions 1, 2, 4
• Adherence to apparently nonfunctional routines or rituals 1
• Encompassing preoccupations with restricted topics or objects 1
• Persistent preoccupation with parts of objects rather than their intended use 1
• Self-stimulatory behaviors, which may include self-injury 1
• Hyper- or hypo-reactivity to sensory input, including atypical sensory behaviors 2, 7

Age-Specific Presentations

Infants (0-12 months)

• May seem "too good" and undemanding 1
• Between 6-12 months: less frequent orienting to name, reduced social smiling, abnormal gaze patterns, and less interest in interacting with others 3
• Atypical trajectories showing relatively typical development in the first year followed by declining acquisition of new skills during the second year 3

Toddlers (12-24 months)

• Difficult eye contact, no or very little social smiling 3
• Minimal exploration of toys, atypical sensory behaviors 3
• Repetitive/atypical motor behaviors become more evident 3
• Decreased variety in types of social interaction gestures used 3

Preschool-age children (2-5 years)

• Marked lack of interest in peers 1
• Absent or severely delayed speech and communication 1
• Restricted interests become more prominent 1
• Poor eye contact remains a hallmark feature 4

School-age and adolescent children

• Social and communication skills may increase but deficits persist 1
• Problems with change and transitions may become more prominent 1
• Higher-functioning individuals may develop anxiety symptoms and depression 3

Critical Diagnostic Considerations

Two behaviors consistently differentiate autistic children from language-impaired peers: pointing for interest and use of conventional gestures 1

• The male-to-female ratio is approximately 4:1, though females with autism tend to have more severe intellectual disability 1
• Approximately 30-50% exhibit intellectual disability of varying severity 3, 2
• Verbal skills are typically more impaired than nonverbal skills in classic presentations 3, 2
• The presence of communicative speech by age 5 years is a positive prognostic indicator, while its absence is a negative predictor 1, 4

Common Co-occurring Features

• Epilepsy affects 20-25% of children with autism, with EEG abnormalities present in many 1
• Behavioral difficulties including hyperactivity, self-injury, aggression, and affective symptoms 3
• Attentional difficulties reflecting cognitive, language, and social problems 3
• Anxiety and depression, particularly in higher-functioning individuals and adolescents 3, 6
• Gastrointestinal problems and sleep disturbances 6, 8
• Increased risk for accidental death, particularly drowning 1

Common Pitfalls to Avoid

Clinicians must not delay evaluation based on "wait and see," as early identification enables timely intervention with significantly improved developmental outcomes 2. The absence of definitive behavioral or diagnostic markers in infants under 12 months does not preclude monitoring developmental trajectories, which may be more sensitive than single-point assessments 3. Caregivers should be encouraged to raise concerns if developmental milestones in social-emotional development, motor skills, language, and problem-solving are not being met 3.