ADHD is common in adults, and many people are first diagnosed after they grow up. CDC estimates that 6.0% of U.S. adults, about 15.5 million people, had a current ADHD diagnosis in late 2023, and more than half of them were diagnosed at age 18 or older. In adults, ADHD often shows up as disorganization, forgetfulness, and inner restlessness rather than obvious hyperactivity.
Key takeaways
- CDC reported that 6.0% of U.S. adults (about 15.5 million) had a current ADHD diagnosis in October and November 2023. The numbers are self-reported, so treat them as estimates.
- More than half of adults with ADHD (55.9%) were diagnosed at age 18 or older.
- NIMH says inattention tends to continue with age, while hyperactivity and impulsivity are more likely to decline. That is one reason adult ADHD can look different from childhood ADHD.
- Diagnosis depends on history. Symptoms must have started before age 12, and a primary care provider or mental health professional can make the diagnosis.
- About 36.5% of adults with current ADHD received no treatment in the past 12 months, according to the same CDC report.
How common is ADHD in adults?
CDC's most recent estimate comes from a survey run by the National Center for Health Statistics in October and November 2023. About 7,000 adults answered two questions: has a health professional ever diagnosed you with ADHD, and do you have it now? From those answers, CDC estimated that 6.0% of adults, or roughly 1 in 16, had a current diagnosis. Among those adults, 55.9% said they were diagnosed at age 18 or older.
The report also lists limits. The diagnoses were not checked against medical records, and low survey response rates may mean some groups are underrepresented.
Older NIMH figures are lower. A national survey done from 2001 to 2003 found that 4.4% of adults ages 18 to 44 had ADHD, and 8.1% had it at some point in their lives. The surveys used different years, ages, and methods, so the numbers do not line up neatly. What they agree on is that ADHD affects a small share of adults, not a large share. NIMH also notes that about one-third of children diagnosed with ADHD still have it as adults.
Why is ADHD in adults so often missed?
ADHD starts in childhood, but it is not always noticed there. NIMH says it may be missed for several reasons, including milder symptoms, a supportive home or school, or simple lack of recognition. It adds that symptoms in girls and women are especially likely to have been missed in childhood.
CDC also points out that symptoms can change over time. Hyperactivity may fade, or turn into feeling restless on the inside. Symptoms may also become more severe when the demands of adulthood grow, such as a demanding job, a household to run, or children of your own. Some people manage well while school or family provides structure, then struggle when that support changes.
What does ADHD look like in adults?
NIMH groups adult symptoms into inattention, hyperactivity, and impulsivity. Examples include:
- Being easily distracted and having trouble paying attention
- Disorganization, procrastination, and poor time management
- Forgetting daily tasks or often losing things
- Trouble focusing on large projects, following instructions, or multitasking
- Interrupting others or talking a lot
- Feeling restless or having trouble sitting still
- Preferring quick rewards to bigger ones later
CDC adds that adults may find it hard to finish long tasks unless the task interests them, and that symptoms can cause trouble at work, at home, or in relationships.
Everyone has some of these moments. For ADHD, NIMH says the behaviors are more severe, more frequent, and more persistent than in people without the disorder. They show up across multiple situations and last at least six months. NIMH also notes that ADHD often occurs with other mental health conditions, and that sleep problems affect up to 70% of adults with ADHD.
How is ADHD diagnosed in adults?
There is no single test. CDC says diagnosis is a multi-step process, and that conditions such as anxiety, depression, sleep problems, substance misuse, and learning disabilities can cause similar symptoms. A provider has to consider those too.
Because the diagnosis depends on childhood history, NIMH says a provider may:
- Talk with people who know you well, such as a partner, family members, or friends
- Review school reports or other childhood records
- Use clinical interviews, rating scales, or symptom checklists
- Give psychological tests of memory, planning, and reasoning
- Review your mood and medical history
The main rules are these. Symptoms must have begun before age 12. Adults and teens over 16 need five symptoms, instead of the six required for younger children. The symptoms must last at least six months and affect at least two areas of life, such as home, school, or work.
What treatment options exist?
CDC and NIMH both describe two main paths: medication, most often stimulants, and therapy such as behavioral or cognitive behavioral therapy. NIMH also lists ADHD or life coaching to build executive function skills such as planning and organizing, regular exercise, and workplace accommodations under the Americans with Disabilities Act. CDC notes that people with ADHD can ask their employer for accommodations, and that effective plans include close follow-up and changes along the way. Which approach fits you is a decision for you and your prescriber.
In the 2023 survey, 50.4% of adults with current ADHD had been prescribed ADHD medication in the past year, and 33.4% took a stimulant. Among stimulant users, 71.5% said they had trouble filling a prescription because the medication was not available. If that sounds familiar, our post on the ADHD medication shortage status explains what the FDA list shows, and how to find Adderall in stock walks through the phone calls. Needle can also phone pharmacies for you and report which ones say they have your exact drug, strength, and form. You can start a search at app.findneedle.co.
What should I do if I think I have ADHD?
CDC's first suggestion is to talk with a healthcare provider about whether your symptoms fit an ADHD diagnosis. A provider may diagnose you directly or refer you to a mental health professional. A few things can help the visit go better:
- Write down what you notice now, and where it causes problems.
- Jot down what you remember from childhood, and ask a parent or sibling what they recall.
- Bring old report cards or school notes if you have them.
- Mention sleep, mood, and anything else going on in your life.
NIMH says it is never too late to seek a diagnosis and treatment. For a wider view of symptoms across ages and how to support someone, see our ADHD awareness guide.
Frequently asked questions
Can you develop ADHD as an adult?
NIMH describes ADHD as a developmental disorder, which means symptoms must begin in childhood. Many adults are diagnosed late because the signs were missed earlier. If attention problems are new, other causes such as anxiety, depression, or sleep problems are possible, so tell your provider about any recent changes.
Does ADHD go away with age?
Not always. NIMH says inattention often continues into adulthood, while hyperactivity and impulsivity are more likely to decline. NIMH also cites research suggesting about one-third of children diagnosed with ADHD continue to have it as adults.
Who can diagnose ADHD in an adult?
According to NIMH and CDC, a primary care provider or a mental health professional such as a psychologist or psychiatrist can diagnose ADHD. A primary care provider may refer you if the picture is complicated.
Can an online quiz tell me if I have ADHD?
A quiz can help you put your experiences into words, but it cannot diagnose ADHD. CDC says there is no single test, and that a provider needs to look at your history and rule out other causes.