Assessment and Diagnostic Approach for a 15-Year-Old Male with Suspected ASD
A comprehensive multidisciplinary assessment is essential for accurate diagnosis of Autism Spectrum Disorder (ASD) in adolescents, focusing on social communication deficits and restricted/repetitive behaviors as core diagnostic features. 1
Initial Screening and History Collection
Key Questions to Ask:
Social Communication and Interaction:
- Difficulty maintaining eye contact or appropriate facial expressions
- Problems with back-and-forth conversation
- Challenges in developing and maintaining relationships
- Difficulty understanding social cues and nonverbal communication
- Limited sharing of interests or emotions with others
Restricted/Repetitive Behaviors:
- Presence of stereotyped movements or repetitive speech
- Rigid adherence to routines or ritualized patterns
- Highly restricted, fixated interests with abnormal intensity
- Unusual sensory interests or sensitivities
Developmental History:
- Age when symptoms first appeared
- Pattern of skill development (regression, plateau, or atypical progression)
- Previous interventions and their effectiveness
- School performance and social functioning
- Family history of ASD or other neurodevelopmental disorders
Diagnostic Evaluation Process
1. Standardized Assessment Tools
The most evidence-based diagnostic instruments with highest sensitivity and specificity include:
- Autism Diagnostic Observation Schedule (ADOS) - A semi-structured assessment of communication, social interaction, and play 1
- Autism Diagnostic Interview-Revised (ADI-R) - A structured interview conducted with parents/caregivers 1
These tools should be administered by professionals trained in their use, as they provide the highest diagnostic accuracy when used in combination.
2. Medical Assessment Components
- Complete physical examination
- Hearing screen to rule out hearing loss
- Genetic testing:
- Chromosomal microarray (24% diagnostic yield)
- G-banded karyotype (2.5% diagnostic yield)
- Fragile X testing (0.57% diagnostic yield) 1
- Wood's lamp examination for signs of tuberous sclerosis
- Consider EEG if seizures are suspected 1
3. Cognitive and Language Assessment
- Intellectual/cognitive assessment to identify strengths and weaknesses
- Receptive and expressive language evaluation
- Pragmatic language assessment
- Processing speed and working memory assessment 1
Multidisciplinary Team Approach
The ideal assessment team should include:
- Psychologist
- Physician (developmental pediatrician, neurologist, or psychiatrist)
- Speech/language pathologist 1
Additional specialists may be needed based on presenting symptoms:
- Occupational therapist (for sensory processing concerns)
- Educational specialist (for academic planning)
Important Considerations for Adolescents
- Symptoms may present differently in adolescents compared to younger children
- Social communication difficulties often become more apparent during adolescence when social demands increase
- Restricted interests may appear as intense hobbies or preoccupations
- Assess for co-occurring conditions common in adolescents with ASD:
- Anxiety disorders
- Depression
- ADHD
- Learning disabilities
Follow-up and Management Planning
After diagnosis, the assessment should inform:
- Educational accommodations and IEP/504 planning
- Social skills interventions
- Communication therapy needs
- Behavioral interventions for restricted/repetitive behaviors
- Consideration of medication for specific symptoms (e.g., irritability may be treated with risperidone in some cases) 2
Pitfalls to Avoid
- Overlooking subtle presentations: High-functioning adolescents may have developed compensatory strategies that mask symptoms
- Gender bias: ASD may present differently in males versus females
- Attributing symptoms solely to other conditions: Many adolescents have co-occurring conditions that can complicate diagnosis
- Cultural factors: Be aware of cultural differences in social communication norms
- Relying solely on parent report: Direct observation and self-report are crucial in adolescents
The diagnostic process should be thorough but efficient to allow for timely intervention, as early identification and appropriate support are critical for improving long-term outcomes in terms of morbidity, mortality, and quality of life for adolescents with ASD.