Evaluating a Child for Autism Spectrum Disorder and ADHD
Core Questions to Establish ASD Diagnosis
When evaluating for ASD, focus your questions on identifying fundamental deficits in joint attention, nonverbal communication, and social reciprocity—these are the key features that distinguish ASD from ADHD. 1
Social Communication and Interaction Deficits
Does the child respond to their name when called? Failure to respond to name at 12 months has 86% specificity for ASD and is highly distinguishing from other developmental delays including ADHD 1
Does the child point to share interest or show you things? Deficits in joint attention initiation—showing significantly fewer nonverbal behaviors to initiate shared experiences—are a key marker of ASD 1
How does the child use eye contact? Qualitatively impaired eye contact (less frequent and poorly modulated) characterizes ASD, not simply reduced eye contact due to distractibility as seen in ADHD 1
Does the child use conventional gestures like waving, nodding, or shaking their head? Impaired conventional gesture use is characteristic of ASD but preserved in ADHD 1
Does the child use your hand as a tool (e.g., moving your hand to open a door)? Using others' bodies as tools is characteristic of ASD but not ADHD 1
Repetitive Behaviors and Emotional Regulation
What repetitive behaviors does the child display, and when do they occur? ASD repetitive behaviors (hand flapping, finger flicking, rocking, spinning) serve self-regulatory functions and are ego-syntonic, often increasing with stress or excitement 1. In contrast, ADHD repetitive behaviors (fidgeting, difficulty remaining seated, excessive talking) are driven by impulsivity and hyperactivity 2, 1
How does the child express positive and negative emotions? Children with ASD demonstrate lower positive affect and higher negative affect, indicating difficulties with emotional regulation that differ qualitatively from ADHD impulsivity 1
Core Questions to Establish ADHD Diagnosis
Symptom Onset and Chronicity
When did you first notice these symptoms? ADHD symptoms must have onset before age 12 and be present across multiple settings since childhood 2. This is mandatory—adolescents presenting for evaluation must have documented or reported manifestations before age 12 2
Have these symptoms been present for at least 6 months? Duration of at least 6 months is required for diagnosis 2
Cross-Setting Documentation
Obtain information from at least two teachers or other observers (coaches, school guidance counselors, community activity leaders) in addition to parents. 2 This is non-negotiable for documenting symptoms in more than one major setting.
How does the child's behavior manifest at school? Ask teachers about specific inattention symptoms (difficulty sustaining attention, not listening when spoken to directly, failing to finish schoolwork) and hyperactivity/impulsivity symptoms (fidgeting, leaving seat, interrupting) 2
How does the child's behavior manifest at home? Ask parents about the same symptom domains in home settings 2
For adolescents: Expect variability in ratings between different classrooms and teachers—identifying reasons for this variability provides valuable clinical insight 2
Functional Impairment
- How do these symptoms interfere with academic performance, social relationships, and daily functioning? Document specific examples of impairment in multiple domains 2
Mandatory Screening for Comorbid and Mimicking Conditions
Screen systematically for all of the following conditions, as they frequently co-occur with both ASD and ADHD and fundamentally alter treatment approach. 2
Psychiatric Comorbidities
Depression and anxiety: Ask about mood changes, worry, social withdrawal, sleep changes, appetite changes. Approximately 14% of children with ADHD have comorbid anxiety disorders 2, 3. The risks increase substantially during adolescence 2
Trauma history: Ask specifically about trauma experiences, posttraumatic stress disorder, and toxic stress. PTSD can manifest with impulsivity, hyperarousal, and attention difficulties that closely mimic ADHD 3, 4. Ask: "Has the child experienced or witnessed any traumatic events?" 3
Oppositional defiant disorder and conduct disorders: Ask about defiant behavior, rule-breaking, aggression 2
Substance use (adolescents): Marijuana and other substances can produce effects that mimic ADHD symptoms. Adolescents may also feign symptoms to obtain stimulant medications 2, 3
Developmental and Learning Conditions
Learning disabilities and language disorders: Ask about academic struggles, reading difficulties, speech/language delays 2
Sleep disorders: Ask about snoring, restless sleep, daytime sleepiness. Sleep disorders produce daytime hyperactivity and inattention that resolves with treatment of the underlying sleep problem 2, 3
Tic disorders: Ask about repetitive movements or vocalizations 2
Age-Specific Considerations
Preschool-Aged Children (4-5 years)
Use focused checklists and rating scales to aid diagnostic evaluation, as observing symptoms across multiple settings is challenging when children don't attend preschool or childcare 2
Recommend parent training in behavior management (PTBM) before finalizing diagnosis. PTBM has documented effectiveness regardless of etiology, and the intervention's results inform subsequent diagnostic evaluation 2
Adolescents (12-18 years)
Establish that symptoms were present before age 12 through parent report or school records. This is mandatory and non-negotiable 2
Screen aggressively for substance use, depression, anxiety, and risky behaviors. These risks increase substantially during adolescence 2
Recognize that adolescents minimize their own problematic behaviors and their self-reports often differ from other observers 2
Critical Diagnostic Pitfalls to Avoid
Never assign an ADHD diagnosis based on single-setting reports. Failing to obtain information from multiple settings before concluding ADHD criteria are met leads to misdiagnosis 3
Never diagnose ADHD when symptoms are better explained by trauma, substance use, or other psychiatric conditions. This results in inappropriate treatment and missed opportunities to address the true underlying cause 3
Never overlook the possibility of co-occurring ASD and ADHD. About half of children with ASD also meet criteria for ADHD, and the DSM-5 now permits both diagnoses 2, 5. Screen for ADHD symptoms in every child with ASD 1
Never fail to screen for comorbidities. The majority of children with ADHD meet criteria for another mental disorder, making comorbidity screening essential rather than optional 3
Standardized Assessment Tools
For ASD Evaluation
- M-CHAT for screening at 24 months 1
- ADOS (Autism Diagnostic Observation Schedule) for direct observation of social-communication behaviors 2
- ADI-R (Autism Diagnostic Interview-Revised) for developmental history 2
For ADHD Evaluation
- DSM-5-based ADHD rating scales completed by parents and teachers 2