Can autism spectrum disorder (ASD) develop during the teenage years?

Autism Spectrum Disorder Development During Teenage Years

Autism spectrum disorder (ASD) is typically diagnosed in early childhood, with symptoms usually apparent before age 3, and cannot newly develop during adolescence. 1

Early Onset and Diagnosis Patterns

Autism is characterized by persistent deficits in social communication and interaction, along with restricted, repetitive patterns of behavior, interests, or activities. The diagnostic criteria for ASD require that symptoms be present in early developmental periods, though they may not become fully manifest until social demands exceed limited capacities 1, 2.

Key points about ASD onset:

• According to the American Academy of Child and Adolescent Psychiatry, ASD symptoms typically emerge in early childhood, with most cases being identifiable by 24 months of age 1
• The diagnosis requires symptoms to be present in early development, though they may not be recognized until later 1
• Preschool children with autism typically present with:
  • Marked lack of interest in others
  • Failures in empathy
  • Absent or severely delayed speech
  • Resistance to change
  • Restricted interests
  • Stereotyped movements 1

What Happens During Adolescence

Rather than new development of ASD, what may occur during teenage years is:

1. First diagnosis of pre-existing ASD: Some individuals with milder forms of ASD may not be diagnosed until adolescence when social demands increase and expose previously unrecognized difficulties 3

2. Behavioral changes in existing ASD: During adolescence, a small number of individuals with autism make marked developmental gains, while another subgroup may experience behavioral deterioration (e.g., tantrums, self-injury, or aggression) 1

3. Late recognition of symptoms: Research shows that "late-diagnosed" autistic children (diagnosed between ages 8-14) often have high levels of mental health and social difficulties prior to diagnosis, which tend to worsen as they enter adolescence 3

Why Late Diagnosis Occurs

Several factors contribute to delayed diagnosis of ASD:

• Higher cognitive functioning may mask symptoms in early childhood 4
• Girls with ASD are more likely to be diagnosed later than boys 5
• Children with better baseline adaptive skills are more likely to have their ASD symptoms recognized later 5
• Social demands increase during adolescence, making previously subtle social deficits more apparent 3

Screening and Identification

The American Academy of Pediatrics recommends:

• Universal screening for ASD at 18 and 24 months 1
• Intensified surveillance for siblings of children with ASD, who have an estimated 14-18% recurrence risk 1
• Immediate referral for diagnostic evaluation when screening is positive 1

Important Considerations

• Regression can occur: Some children with ASD experience developmental regression (loss of previously acquired skills), but this typically happens in early childhood, not adolescence 1
• Differential diagnosis: In teenagers, it's important to differentiate ASD from other conditions like anxiety disorders, obsessive-compulsive disorder, or schizophrenia 1
• Comorbidities: Adolescents with ASD often have comorbid conditions including depression (20%), anxiety (11%), and sleep difficulties (13%) 2

Conclusion

While ASD symptoms may become more apparent or change during adolescence, the disorder itself does not newly develop during the teenage years. What appears to be "new" autism in teenagers is typically the recognition of a pre-existing condition that was previously undiagnosed or misdiagnosed.