Yes, you can have both ADHD and autism at the same time. The two conditions co-occur frequently, with roughly 28% of autistic individuals also meeting criteria for ADHD. Since 2013, clinicians have been able to officially diagnose both in the same person, and growing research into shared genetics and brain patterns helps explain why they overlap so often.
Why a Dual Diagnosis Was Once Off the Table
Before 2013, the diagnostic manual used by psychiatrists and psychologists explicitly prohibited giving someone both diagnoses. If a person had autism, any ADHD-like symptoms were considered part of the autism rather than a separate condition. This left many people with incomplete diagnoses and, often, incomplete treatment.
The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published in 2013, changed that rule. Clinicians could now recognize what researchers had been observing for years: these are two distinct conditions that frequently show up together, each requiring its own attention. That single rule change opened the door for millions of people to get a more accurate picture of how their brain works.
How Common the Overlap Is
Studies looking at ADHD symptoms among autistic children (without intellectual disability) report prevalence estimates that vary widely depending on how symptoms are measured, but even the most rigorous studies find rates between 27% and 95%. That enormous range reflects differences in assessment tools and study design, but the bottom line is consistent: co-occurrence is the norm, not the exception. Looking from the other direction, about 29% of adults with autism in one study also met full criteria for ADHD, with the combined and inattentive types being the most common presentations.
Shared Genetics Behind the Overlap
The high co-occurrence rate isn’t a coincidence. ADHD and autism share genetic risk factors at the molecular level. Researchers studying families where both conditions appear have identified regions on chromosomes 12 and 17 that are significantly linked to both. One gene in particular, KDM6B on chromosome 17, ranks as a top risk gene for both conditions. It plays a role in how genes get switched on and off during brain development through a process called histone modification.
Genome-wide studies have found 16 genetic variants associated with ADHD that also appear to be involved in autism, and 25 autism-linked variants that show up in ADHD. Shared biological pathways include those involved in how brain cells communicate through ion channels and how certain cellular structures develop. In short, the two conditions draw from a partially overlapping genetic toolkit, which is why they so often travel together in families.
What Happens in the Brain
Brain imaging research reveals that autistic children who also have significant attention problems show distinct patterns compared to autistic children without those problems. The strongest difference appears in the frontoparietal network, a set of brain regions spanning the prefrontal cortex and parts of the parietal lobe that supports cognitive control, including the ability to inhibit impulses and direct attention. In autistic children with elevated attention difficulties, connectivity within this network is weaker, and its connections to language-processing and default mode networks are also reduced.
Interestingly, autistic children without attention problems show frontoparietal connectivity that looks similar to neurotypical children. This suggests the attention-related brain differences aren’t simply part of autism itself but represent a genuinely additional layer. Other circuits, like the salience network (involved in deciding what deserves your attention), don’t seem to differ in young children with the dual presentation, though they may diverge later in adolescence.
Where Symptoms Overlap and Where They Don’t
One reason the combination is tricky to identify is that ADHD and autism share surface-level features while differing in their underlying causes. Both can involve difficulty in social situations, trouble with transitions, emotional dysregulation, and problems with executive function like planning, working memory, and mental flexibility. A 2023 meta-analysis comparing executive function profiles in children and adolescents with ADHD versus autism found no significant differences between the two groups across attention, flexibility, working memory, processing speed, or response inhibition. Both groups performed worse than neurotypical peers, but their profiles looked remarkably similar to each other.
Social difficulties illustrate where the distinction matters most. In ADHD, social problems tend to stem from inattention: missing social cues because you weren’t tracking the conversation, interrupting impulsively, or struggling to maintain friendships because you forget to follow up. In autism, social challenges are more rooted in differences in how social information is processed, including reduced social-emotional reciprocity, difficulty reading nonverbal cues, and less intuitive understanding of unspoken social rules. The DSM-5 specifically notes that “the social dysfunction and peer rejection seen in individuals with ADHD must be distinguished from the social disengagement, isolation, and indifference to facial and tonal communication cues seen in individuals with ASD.” When someone has both conditions, both drivers are present, which can make social interaction especially exhausting.
Why It’s Often Missed or Misdiagnosed
Many people with both conditions go years with only one diagnosis, or none at all. One major reason is masking, the conscious or unconscious effort to hide symptoms in social situations. Masking has been well documented in autism, where individuals learn to mimic neurotypical social behavior at significant personal cost. Emerging evidence shows that people with ADHD also engage in masking, developing compensatory strategies to appear more organized, attentive, or socially fluent than they feel. When someone with both conditions masks effectively, neither condition may be immediately visible to a clinician during a brief evaluation.
Diagnostic confusion also runs in the other direction. A child who can’t sit still and blurts out answers might get an ADHD diagnosis while their rigid routines and intense special interests go unnoticed. Conversely, an autistic child whose inattention is attributed entirely to being “in their own world” might never be evaluated for ADHD. The symptom overlap in executive function makes it even harder to tease apart which condition is driving which behavior, especially since 20% to 65% of children with ADHD display clinically significant autistic traits like difficulty adapting to change and repetitive behaviors.
How Treatment Differs With Both Conditions
A dual diagnosis doesn’t mean treatment is twice as complicated, but it does require a more tailored approach. One common concern is whether stimulant medications, the standard first-line treatment for ADHD, work as well in people who also have autism. Research comparing the two groups found that autistic children with ADHD responded just as well to stimulants as children with ADHD alone, with significant improvements in hyperactivity, impulsivity, inattention, and aggression. Importantly, stimulants did not worsen tics or repetitive behaviors in the autistic group. The side effect profile was actually narrower: while children with ADHD alone experienced nausea, dizziness, headaches, and sleep difficulties, sleep difficulties were the only side effect that emerged significantly in the dual diagnosis group.
Beyond medication, people with both conditions often benefit from supports that address each condition’s unique contributions. Structured routines and sensory accommodations help with the autism side, while strategies for time management, task initiation, and impulse control target ADHD. Occupational therapy can address sensory processing difficulties, which are common in both conditions and tend to compound when both are present. Sensory sensitivity is linked to higher perceived stress and core burnout symptoms in working adults, making sensory management a practical priority rather than a luxury.
Living With Both as an Adult
Adults with both ADHD and autism, sometimes informally called “AuDHD” in online communities, often describe a push-pull experience. The ADHD side craves novelty and stimulation while the autism side needs predictability and routine. Impulsivity clashes with a preference for sameness. The result can be an internal tug-of-war that’s exhausting to manage, especially in workplaces and social settings designed for neurotypical brains.
Sensory processing plays a central role in daily life. Sensitivity to sound, light, texture, or proximity to other people can affect everything from workplace productivity to sleep quality. Adults with heightened sensory sensitivity report higher levels of exhaustion, cognitive impairment, and psychosomatic complaints. Missing sensory input, like not hearing a phone ring or not noticing someone approaching, can create friction at work, while overreacting to sensory intrusions like a colleague standing too close can strain relationships. Recognizing these patterns as neurological rather than personal failings is often the first step toward building a life that actually fits.