ADHD and Autism: Can You Have Both? What Dual Diagnosis Looks Like

You got diagnosed with ADHD, started treatment, and some things improved. But not everything. Social situations still exhaust you in ways that ADHD doesn't quite explain. Sensory sensitivities persist. Something still doesn't add up.

This is one of the most common paths to a dual ADHD and autism diagnosis: a first diagnosis that fits partially, followed by the realisation that a second condition has been hiding in the overlap.

Can ADHD and Autism Occur Together?

Yes. Current research estimates that between 50 and 70 percent of autistic individuals also meet criteria for ADHD, and a substantial proportion of people with ADHD show autistic traits.

Until 2013, the DSM explicitly prohibited dual diagnosis. If you had autism, you couldn't also be diagnosed with ADHD under the same diagnostic framework. The DSM-5 removed that exclusion, reflecting decades of clinical evidence that the two conditions co-occur at rates far too high to be coincidental.

This change matters enormously for adults seeking assessment today. If you were evaluated before 2013, your clinician may have been forced to choose one diagnosis even if both were present. Many adults are now returning for reassessment with this updated understanding.

How Are ADHD and Autism Similar, and Different?

Both conditions affect attention, but for different reasons. ADHD involves difficulty regulating attention across the board: you struggle to focus on things that aren't immediately engaging. Autism involves intense, focused attention on specific interests, sometimes to the exclusion of everything else.

Both can cause social difficulties. ADHD-related social problems tend to stem from impulsivity (interrupting, missing social cues because you're distracted). Autism-related social difficulties stem from differences in how social information is processed (difficulty reading tone, uncertainty about unwritten social rules, finding small talk confusing or pointless).

Executive function challenges show up in both conditions, but the underlying mechanisms differ. With ADHD, you know what you need to do but can't initiate or sustain the effort. With autism, you may struggle with flexible thinking, finding it difficult to shift between tasks or adapt when plans change.

Sensory processing differences are more strongly associated with autism but are increasingly recognised in ADHD as well. The overlap here is real and clinically meaningful.

What Are the Signs of Both ADHD and Autism in Adults?

Adults with both conditions often describe a contradictory internal experience: simultaneously chaotic and rigid, impulsive and rule-bound, socially motivated but socially exhausted.

Common patterns include deep, intense interests that shift periodically (the ADHD-driven novelty seeking meets autistic hyperfocus), difficulty with both routine tasks and unexpected changes, social fatigue that goes beyond introversion, and emotional responses that feel disproportionate to the situation.

Sensory sensitivities combined with inattention create distinctive challenges. You might be overwhelmed by fluorescent lighting (an autistic sensory sensitivity) while simultaneously unable to notice that your phone has been buzzing for five minutes (ADHD inattention).

People with both conditions frequently report that they've never fully identified with either diagnosis alone. Parts of ADHD fit, parts of autism fit, but neither captures the whole picture.

How Is a Dual ADHD and Autism Diagnosis Made?

A dual diagnosis requires a comprehensive assessment that evaluates both conditions independently rather than assuming one explains all symptoms.

The psychologist uses separate diagnostic instruments for each condition. ADHD assessment involves clinical interview, rating scales, and sometimes cognitive testing focused on attention and executive function. A thorough assessment examines where symptoms overlap and where they diverge.

This is not straightforward clinical work. The assessor needs to disentangle which symptoms belong to which condition and which belong to both. Inattention during a social interaction could be ADHD, could be autistic disengagement from a socially demanding situation, or could be both.

Developmental history is critical. Autism is present from early childhood. ADHD symptoms also emerge early. But the way these conditions interact evolves over time, and an experienced clinician will trace that trajectory through childhood, adolescence, and adulthood.

Why Is Dual Diagnosis Often Missed in Adults?

Three factors conspire against accurate identification.

First, masking. Adults with both conditions have spent decades developing compensatory strategies. High intelligence, strong verbal skills, and sheer determination can conceal both conditions from casual observation. The effort required to maintain these strategies is invisible to everyone except the person doing it.

Second, diagnostic overshadowing. Once one diagnosis is made, clinicians may attribute all symptoms to that single condition. If you're diagnosed with ADHD, your social difficulties get explained as "ADHD-related" even when they have a distinctly autistic quality. If you're diagnosed with autism, your inattention gets chalked up to disinterest rather than recognised as a separate attentional difficulty.

Third, gendered presentation. Women and gender-diverse individuals are underdiagnosed in both conditions. Autistic masking tends to be more extensive in women, and the ADHD presentation most common in women (predominantly inattentive) is the most frequently overlooked.

What Does Treatment Look Like When You Have Both ADHD and Autism?

Treatment must address both conditions, and the approach differs from treating either one alone.

ADHD medication (stimulants or non-stimulants) can improve attention and reduce impulsivity, which often makes autistic coping strategies more effective. However, some autistic adults find that stimulant medication increases anxiety or sensory sensitivity, so dosing requires careful monitoring and adjustment.

Therapy for dual diagnosis needs to be adapted. Standard CBT approaches work well for ADHD-related patterns like procrastination and disorganisation. But the social communication and sensory components need autism-informed strategies: understanding your sensory profile, building sustainable social energy budgets, and developing self-advocacy skills.

Environmental modifications matter more with dual diagnosis than with either condition alone. This might mean structuring your day to balance the ADHD need for variety with the autistic need for predictability, or creating a workspace that addresses both sensory sensitivities and distractibility.

If you've been partially treated for one condition and something still feels off, a comprehensive assessment covering both ADHD and autism is the most useful next step.