An ADHD diagnosis is based on reported signs, symptoms, behavior, and history rather than any single test. ADHD symptoms can vary depending on the exact type and severity of the condition. Though many people lose focus, get distracted, and act impulsively on occasion, these behaviors are more severe and more frequent for people with ADHD. Without proper identification and treatment, these behaviors negatively affect their quality of life at work, at school, and at home. According to the CDC and National Institute of Mental Health (NIMH), children who are hyperactive may:

Talk excessivelyFidget and squirmBe in constant motionHave significant trouble sitting quietly or stillRun, jump, or climb around constantly

Children who experience impulsivity may:

Be impatientHave difficulty taking turns or waiting for their turnFrequently interrupt othersAct or speak without thinking

Children who experience inattention may:

Be easily distracted or become easily boredHave trouble focusingHave problems completing tasks or activitiesDaydream frequentlyStruggle with following instructionsSwitch from one activity to another frequentlyBe forgetfulHave difficulty processing information quickly

In preschool-age children, the most common symptom of ADHD is hyperactivity-impulsivity, say NIMH experts.

ImpulsivenessLack of organization and difficulty prioritizing tasksDifficulty focusing and following through on thingsPoor time management and planning skillsRestlessnessFrequent mood swingsDifficulty coping with stress

To receive a diagnosis of ADHD, children and adults must meet the criteria laid out in the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5). Children who are age 16 or younger must have six or more signs of the disorder for at least six months to a degree that’s inconsistent with their developmental level, according to the CDC. Older adolescents and adults (age 17 and older) must exhibit five or more symptoms to receive the diagnosis. ADHD symptoms include the following, say CDC experts.

Inattention

Lack of attention to details, or careless mistakesTrouble maintaining attention to tasks or play activitiesAppears not to listen when spoken to directlyStruggles to follow-through on instructionsDifficulty completing school assignments, chores, or workDifficulty organizing tasks and activitiesAvoidance and reluctance to do tasks that require sustained mental effort, such as homeworkMisplaces things that are necessary for certain tasks and activitiesEasily distracted by irrelevant information and other extraneous stimuliForgetful in daily activities

Hyperactivity and Impulsivity

Fidgets or squirms in their seatStruggles to sit still or remain seated when it’s expectedRuns or climbs in situations when it’s not appropriate (this may manifest as restlessness in teens or adults)Often unable to play quietlyIs frequently “on the go” or acts like they’re “driven by a motor”Talks excessivelyInterrupts or blurts out an answer before a question has been fully askedTrouble waiting their turnIntrudes on others (In children, this could mean interrupting others’ games. In adults this may involve intruding on conversations.)

For an ADHD diagnosis, these symptoms must occur in two or more settings (such as the home, school, or work), and must clearly interfere with the person’s social life, schoolwork, or job. In addition, several ADHD symptoms must have been present before age 12.

Subtypes of ADHD

There are three kinds of presentations of ADHD, determined by the types of symptoms that occur.

Predominantly inattentive presentation Mostly symptoms of inattention, and few to no symptoms of hyperactivity-impulsivity, have been present for the past six months.Predominantly hyperactive-impulsive presentation Mostly symptoms of hyperactivity-impulsivity, and few to no symptoms of inattention, have been present for the past six months.Combined presentation. Enough symptoms to meet both inattention and hyperactivity-impulsivity criteria have been present for the past six months.

An ADHD diagnosis often involves several steps. The doctor may perform a full medical exam and conduct interviews with family members or a child’s teachers to gather a personal history. Once you or your child receives a diagnosis, you can begin proper treatment to manage ADHD symptoms.

Importantly, more than two-thirds of individuals with ADHD have at least one additional coexisting condition, according to Children and Adults With Attention-Deficit/Hyperactivity Disorder (CHADD). In children, it’s particularly important to distinguish between ADHD and other conditions that have similar signs and symptoms, or commonly occur with ADHD. These conditions or behaviors include disruptive behavior disorders like oppositional defiant disorder, learning disorders like dyslexia, medical conditions that interfere with sleep, anxiety, depression, and difficult peer relationships, say CDC experts. Diagnoses can be made by pediatricians or mental health professionals, though children of preschool age or younger are more likely to require an evaluation by a specialist (such as a psychologist, psychiatrist, or developmental pediatrician) to get an accurate diagnosis. The DSM-5 now requires that each diagnosis include an assessment of the severity of the condition, whether it’s mild, moderate, or severe, because severity can change over the course of a lifetime, according to CHADD. Diagnosing ADHD in adults poses its own challenges. While some adults may seek treatment if they suspect they have ADHD symptoms that affect their personal and professional life, some adults not previously diagnosed with ADHD may think their struggles are just a reflection of how they are as a person. Since ADHD onset occurs in early childhood, many adults may regard their symptoms as normal and not a condition that could benefit from treatment requiring diagnosis, according to research published in The Primary Care Companion to the Journal of Clinical Psychiatry. Between the years 1997 and 2016, the percentage of children and adolescents ages 4 to 17 diagnosed with ADHD increased from 6.1 percent to 10.2 percent, according to a study published in August 2018 in JAMA Network Open. Some experts are concerned that the disorder is being overdiagnosed because of societal pressure to treat certain behaviors, and because of increasing performance demands in schools. Others believe that ADHD is simply becoming more widely known, and that with increased awareness, more children are getting the treatment they really need. This organization, led by people with ADHD, provides a free ADHD Starter Kit to help adults with ADHD understand and thrive with their diagnosis. You can also join virtual support groups through its website. Child Mind Institute If you’re seeking care for your child with ADHD, the Child Mind Institute has two in-person locations in New York City and San Francisco, and offers telehealth appointments for people living in New York, New Jersey, and California. It also offers a Complete Guide to ADHD for parents. Children and Adults With Attention-Deficit/Hyperactivity Disorder (CHADD) In addition to its advocacy efforts for public policies that benefit people with ADHD, CHADD offers information for educators and parents of children with this condition. Have a look at its Teacher Training and Video Series and its ADHD Toolkit for caregivers. Learning Disabilities Association of America (LDA) This organization offers ADHD-related educational resources and engages in advocacy efforts on behalf of people with this condition. Check out their latest public policy and advocacy actions. Additional reporting by Deborah Shapiro and Christina Vogt.