ADHD involves differences in attention, impulse control, and activity, while autism involves differences in social communication and repetitive behaviors. They can occur together.
ADHD
Differences in attention, impulse control and hyperactivity. About 6% of adults and 11% of children in the US have an ADHD diagnosis.
Autism
Differences in social communication, sensory processing and repetitive behaviors. About 1 in 31 US 8-year-olds is diagnosed (CDC, 2022 data).
Overlap
They often co-occur. Roughly 30% to 50% of autistic people also have ADHD.
Diagnosis
Both are diagnosed by a clinician based on the DSM-5.
Core features
- ADHD: persistent patterns of inattention, hyperactivity and impulsivity that interfere with daily life, appearing before age 12.
- Autism spectrum disorder: differences in social communication and interaction, plus restricted, repetitive patterns of behavior, interests or sensory sensitivities, starting in early development.
Prevalence
The CDC estimates about 1 in 36 US children aged 8 have autism, and about 1 in 9 children (11.4%) have been diagnosed with ADHD. Autism is diagnosed about four times more often in boys. ADHD is about twice as common in boys than girls.
Co-occurrence
Research shows that about 30% to 50% of autistic people also meet criteria for ADHD, and the DSM-5 (2013) allows both to be diagnosed together.
Shared traits
Difficulty with attention shifts, executive function problems, sensory issues, emotional regulation problems and social challenges.
Key differences
- ADHD attention problems appear as difficulty sustaining focus and distraction, while autism attention often appears as intense focus on specific interests.
- Social difficulties in ADHD often come from impulsivity or inattention. In autism they come from difficulty understanding social cues and reciprocity.
Causes
Both are strongly genetic, with heritability around 70% to 80% for ADHD and often cited at 80% or more for autism. Prenatal and environmental factors also play a role.
Diagnosis
Done by trained clinicians such as psychologists, psychiatrists or developmental pediatricians through interviews, rating scales, observation and developmental history. There is no blood test.
Treatment
- ADHD: stimulant and non-stimulant medication, behavioral therapy, parent training and school support.
- Autism: early intervention, speech and occupational therapy, behavioral support and educational plans. Medicines may treat related symptoms such as irritability.
Support
Early evaluation helps children get services. Adults can also be diagnosed later.
Numbers and overlap between the two
In the CDC’s 2022 surveillance, about 1 in 31 eight year old children in the US were identified with autism spectrum disorder, and about 11 percent of US children aged 3 to 17 have ever received an ADHD diagnosis, based on parent reports. Since the DSM-5 in 2013, a person can be diagnosed with both conditions, and studies suggest that between 30 and 50 percent of autistic people also have ADHD symptoms. ADHD symptoms must be present before age 12 and include inattention, hyperactivity and impulsivity, while autism is defined by differences in social communication and restricted, repetitive behaviors, with onset in early development.
How each is supported
ADHD treatment commonly combines behavioral therapy with medication such as methylphenidate or amphetamine based stimulants, which help about 70 to 80 percent of children, according to reviews. Autism supports include speech and occupational therapy, behavioral and developmental programs, school accommodations and help with anxiety or sleep. Neither condition is caused by parenting or by vaccines. Evaluation is done by a pediatrician, psychologist or psychiatrist using interviews, rating scales and observation. Early assessment helps families get services under programs such as IDEA in US schools.
Based on data from the CDC and the American Psychiatric Association
