What additional questions should be asked to confirm Autism Spectrum Disorder (ASD) diagnosis in a patient with social skills deficits, anxiety, attention difficulties, and obsessive-compulsive behaviors?

Confirming ASD Diagnosis: Essential Questions to Ask

To confirm an ASD diagnosis and meet DSM-5 criteria, systematically probe for deficits in social communication/interaction and restricted/repetitive behaviors across multiple contexts, with particular focus on early developmental markers, joint attention failures, and the ego-syntonic nature of repetitive behaviors that distinguish ASD from other conditions. 1

Core Social Communication Deficits to Explore

Early Developmental History (Birth to 24 Months)

• Ask about response to name: Did the child consistently fail to respond when their name was called between 12-24 months? Failure to respond to name at 12 months is highly specific for developmental abnormality including ASD (86% of at-risk infants who failed this showed developmental issues). 2, 3

• Probe for joint attention deficits: Did the child point to show interest (not just to request) between 20-42 months? Did they bring objects to show you? Lack of pointing for interest and absence of conventional gestures at 20-42 months are among the most reliable early differentiators of ASD from language disorders. 2, 1

• Assess early gesture use: Did the child wave bye-bye, nod yes/no, or use other conventional gestures by 20-42 months? Children with ASD show significantly fewer nonverbal behaviors to initiate shared experiences compared to typically developing children. 2

• Evaluate attention to voice: At 24 months, did the child orient to your voice when you spoke from behind or across the room? Deficits in attention to voice at 24 months help differentiate ASD from developmental delay. 2

Current Social Interaction Patterns

• Quantify eye contact quality: Does the child make eye contact only when requesting something, or does it occur spontaneously during social interaction? Is eye contact fleeting, absent, or qualitatively odd (staring without social purpose)? Qualitatively impaired eye contact is a critical ADOS-2 item that distinguishes ASD from ADHD alone. 2, 4

• Assess social-emotional reciprocity: Does the child initiate social interactions for pleasure (not just needs)? Do they respond to others' emotions appropriately? Lower positive affect and higher negative affect at 24 months distinguish children later diagnosed with ASD. 2, 1

• Evaluate peer relationships: Does the child show interest in other children? Can they engage in reciprocal play, or do they prefer solitary activities? Difficulty developing peer relationships is a core DSM-5 criterion. 2, 1

• Probe for use of others as tools: Does the child use your hand as a tool to get objects (e.g., placing your hand on a doorknob) rather than pointing or asking? This behavior is highly specific for ASD. 2, 4

Restricted and Repetitive Behaviors

Stereotyped Motor Movements

• Document specific movements: Does the child engage in hand flapping, finger flicking, body rocking, or spinning? When do these occur (during excitement, stress, or constantly)? These behaviors serve self-regulatory functions in ASD and increase with stress or excitement, unlike ADHD motor behaviors driven by impulsivity. 1, 3, 4

• Assess atypical object use: Does the child line up toys, spin wheels repetitively, or use objects in unusual ways (e.g., only looking at objects from angles)? Atypical object use between 12-24 months is an early marker of ASD. 2

Insistence on Sameness

• Explore rigidity and routines: Does the child become extremely distressed by minor changes in routine, environment, or food presentation? How severe are these reactions? Insistence on sameness is a core DSM-5 criterion. 1, 5

• Assess restricted interests: Are the child's interests abnormally intense or narrow (e.g., memorizing train schedules, fixating on specific topics)? Do these interests interfere with other activities? Highly restricted interests of abnormal intensity distinguish ASD. 1, 5

Sensory Sensitivities

• Document sensory reactivity: Is the child hyper-reactive (covering ears to normal sounds, refusing certain textures) or hypo-reactive (not responding to pain, seeking intense sensory input)? Hyper- or hypo-reactivity to sensory input is a DSM-5 criterion. 1, 3

• Identify unusual sensory interests: Does the child sniff objects inappropriately, stare at lights or spinning objects, or seek specific tactile sensations? Unusual sensory interests are characteristic between 12-24 months. 3

Distinguishing ASD from Comorbid/Differential Diagnoses

Differentiating from ADHD

• Assess engagement patterns: Does the child show consistent difficulty engaging with ALL tasks outside narrow interests (suggests pure ASD), or variable engagement with hyperfocus on interesting tasks but struggle with boring ones (suggests ASD+ADHD)? Approximately 50% of individuals with ASD meet criteria for ADHD. 4, 5

• Evaluate motor behaviors: Are repetitive movements self-regulatory and increase with stress (ASD), or driven by impulsivity and hyperactivity (ADHD)? 4

Differentiating from OCD

• Determine ego-syntonicity: Does the child find their repetitive behaviors pleasurable or distressing? In ASD, repetitive behaviors are ego-syntonic; in OCD, they are ego-dystonic. 2, 1

• Assess age of onset: Did symptoms appear in the first 2 years (ASD) or emerge in later childhood/adolescence (OCD)? 2, 1

• Evaluate social insight: Does the child have developed social insight and understanding (anxiety/OCD) or fundamental social-communication deficits (ASD)? 2

Differentiating from Language Disorders

• Compare pointing and gestures: Children with language disorders typically maintain pointing for interest and conventional gestures, while children with ASD do not. 2

• Assess social motivation: Do social deficits improve when language demands are removed? Language-impaired children show better social engagement when communication barriers are minimized. 2

Developmental Trajectory Questions

• Clarify regression history: Was there ever a period of normal development followed by loss of skills? If yes, at what age and which skills were lost? Regression occurs in some ASD cases but is also seen in Rett syndrome and degenerative CNS disorders. 2

• Document early temperament: Did parents report the child seemed "too good" or undemanding as an infant? This atypical early presentation is common in ASD. 2

• Assess developmental milestones: What were the ages of first words, first phrases, walking? Verbal skills are typically more impaired than nonverbal skills in classic ASD presentations. 2, 1

Comorbidity Screening (Essential Given 90% Have Additional Conditions)

• Screen for anxiety: Does the child show excessive worry, need for reassurance, or inability to relax beyond what's explained by ASD rigidity? Anxiety affects 11% of individuals with ASD versus 5% without. 2, 5

• Evaluate mood symptoms: Are there signs of depression (20% prevalence in ASD vs 7% in general population)? 5

• Assess sleep difficulties: Document sleep onset, maintenance, and quality issues (affect 13% with ASD vs 5% without). 5

• Screen for epilepsy: Any history of seizures or staring spells? Epilepsy affects 21% of individuals with ASD and co-occurring intellectual disability. 5

• Evaluate GI symptoms: Chronic constipation, diarrhea, or abdominal pain? GI disorders are common comorbidities. 1, 5

Functional Impact Assessment

• Quantify adaptive functioning: How does the child manage self-care, daily routines, and age-appropriate responsibilities compared to same-age peers? Cognitive level is the primary driver of behavioral presentation variability. 1

• Assess communication functionality: Can the child communicate basic needs? Do they use language for social purposes or only instrumental requests? 1, 5

• Evaluate impact on family: How do the child's symptoms affect family functioning, sibling relationships, and parental stress? This informs intervention planning. 6

Critical Pitfalls to Avoid

Do not delay evaluation with "wait and see" - early identification enables timely intervention with significantly improved developmental outcomes. 1

Do not attribute all symptoms to ASD alone - systematically screen for comorbid ADHD, anxiety, depression, sleep disorders, GI problems, and epilepsy, as diagnostic overshadowing leads to missed treatable conditions. 1, 4

Do not assume language delay is the primary indicator - social communication differences and joint attention deficits often appear earlier and are more specific for ASD. 3