ADHD symptoms affect social interactions, cause communication differences, and may lead to behavior challenges. The best one-line description of ADHD comes from Russell Barkley, Ph.D., who said, “ADHD is not a disorder of not knowing what to do, it is a disorder of not doing what you know.” This concept also helps distinguish ADHD from autism: Children with ADHD typically know the social rules; they just don’t know how to follow them yet.

SOCIAL CHALLENGES: Children with ADHD usually understand what they’re supposed to do socially, but they don’t yet have the ability to show it in everyday life. Being distracted, impulsive, and off-task affect interactions directly. ADHD kids miss social cues they would otherwise understand — if only they noticed them.

COMMUNICATION CHALLENGES: One often-overlooked aspect of ADHD is the relatively high risk of language delays. Yet even in the absence of an actual delay, ADHD undermines communication. Children lose track of details, are overly talkative, interrupt, stray off topic, and have a hard time keeping track of information. They may speak and process information more slowly than peers, which is not a measure of intelligence but of pacing. Unlike kids with autism, children with ADHD typically understand the pragmatic part of language; ADHD itself gets in the way.

BEHAVIOR CHALLENGES: Behavioral concerns frequently, but not always, occur with ADHD. They involve not following social rules, such as acting impulsively, being overly silly, or disrupting situations in other ways. When peers prefer sticking to one activity, a short attention span may be disruptive on its own. The chronic challenges with organization and planning related to executive function that occur with ADHD have not been as clearly linked to autism alone. If a child with autism struggles a lot with attention or executive function, ADHD may also be present.

The key trait that distinguishes ADHD from autism is the ability to intuitively comprehend the social world. Delays in this skill are the common thread among all diagnoses of autism, regardless of severity. Children with ADHD alone may also struggle socially, but their intuitive understanding is present.