ADHD vs Autism
Two neurodevelopmental conditions with real overlap — what differs, what shares, and which screen to take.
At a Glance
| Core feature | Inattention, hyperactivity, impulsivity | Social-communication difference, restricted interests, sensory differences |
| Onset | Symptoms in childhood; persists in 50–65% of adults | Lifelong; present from early development |
| Prevalence | ~5% of children, ~2.5% of adults | ~1–2% of adults (likely higher; underdiagnosed in women) |
| Co-occurrence | 30–80% of autistic adults also meet ADHD criteria | 30–50% of ADHD adults show autistic traits |
| Primary screen | ASRS-v1.1 (Kessler et al., WHO) | AQ-10 (NICE-recommended) or RAADS-R |
| Sensory issues? | Often (hyposensitivity to boredom) | Often (hypersensitivity to stimuli) |
| Social difficulty? | Yes — interruption, missed cues | Yes — different communication style, masking |
| Best response to | Stimulant medication + behavioral support | Environmental adjustments + therapy/support |
Overview
ADHD and autism are distinct neurodevelopmental conditions that frequently co-occur — recent estimates suggest 30–80% of autistic adults meet ADHD criteria and vice versa. The conditions share some surface symptoms (focus issues, social difficulties, executive function challenges) but differ at the level of underlying mechanisms. This page walks through where they overlap, where they truly differ, and which screening tool fits which suspicion.
When to Use Each
ADHD
Take the ADHD screen if your main concerns are focus problems, time blindness, impulsivity, restlessness, or executive dysfunction that's been present since childhood. Screening positive supports a clinical evaluation for ADHD.
Autism (AQ-10)
Take the AQ-10 if your main concerns are social-communication differences, sensory sensitivities, restricted interests, need for routine, or masking exhaustion that's been lifelong. Screening positive supports a clinical autism evaluation.
Both
Take both if you have mixed symptoms or family history of either condition. Co-occurrence is the rule, not the exception — many adults receive both diagnoses. The screens are short and complement each other.
Quick Decision Tree
- Main concern is focus / time / impulsivity? → ADHD screen
- Main concern is social or sensory difference? → AQ-10
- Both apply? → Take both — co-diagnosis is common
- Childhood symptoms present in both? → Both, plus clinical evaluation
- Family history of either condition? → Screen for both
Frequently Asked Questions
Can someone have both ADHD and autism?
Yes — and it's common. Co-occurrence rates of 30–80% have been reported. Until DSM-5 in 2013, the diagnoses were considered mutually exclusive; now they're recognized as frequently overlapping. The combination is sometimes called 'AuDHD'.
Which is harder to diagnose?
Both are underdiagnosed in adults, especially women. Autism is harder because of masking — adults learn to camouflage social differences. ADHD is harder because adult presentation differs from childhood hyperactivity stereotypes.
What symptoms overlap?
Both can involve: difficulty with social interaction, sensory sensitivities, executive function challenges, emotional regulation difficulties, and atypical attention patterns. The mechanisms differ but surface behavior can look similar.
How do clinicians tell them apart?
Through detailed developmental history, the pattern of symptoms (ADHD = inconsistent attention; autism = consistent difference in social processing), response to interventions, and ruling out alternative explanations.
Should I screen for both?
If you suspect either, yes. The screens are short (3 minutes for AQ-10, 6 minutes for ASRS) and co-occurrence is the rule, not the exception. Better to screen broad than miss a co-diagnosis.
Are medications the same?
No. ADHD responds to stimulants (methylphenidate, amphetamines) and non-stimulants (atomoxetine). Autism has no specific medication — interventions are environmental, therapeutic, and supportive. Co-occurring ADHD in autistic adults usually responds to stimulants.