Symptoms and Diagnosis

Given the fuzzy character of the disorder, the symptoms of ADHD are not always clear cut. Since everyone experiences inattention or impulsivity from time to time, an individual’s symptoms must be persistent to be considered diagnostically relevant and impair function in school, at work, or at home. For children, symptoms must be unusual for the corresponding developmental stage, as some may represent typical behavior for one's age group. (Some evidence suggests that children who are young for their grade are more likely to be diagnosed with ADHD, as they are developmentally behind their peers but subject to the same behavioral expectations.) According to DSM guidelines, for an adult to be diagnosed, symptoms must have emerged before age 12, meaning a thorough medical history is required for an accurate diagnosis.

Clinicians today rely on validated rating scales that are designed to capture ADHD symptoms in a variety of settings such as school, home, or the workplace. A thorough diagnosis will also include a medical history, the ruling out of other physical or mental disorders, and input from others (such as a teacher or spouse) to determine if symptoms are present in multiple domains and are causing measurable challenges for the individual.

Many children are hyperactive or struggle with focus from time to time; this does not mean they have ADHD, and it’s critical that the diagnosis not be made lightly. But children who are rarely able to focus on schoolwork, are significantly more hyperactive than same-age peers (sometimes to the point of endangering themselves or others), and find it immensely difficult to stay organized, keep track of possessions, or remember tasks may benefit from a thorough ADHD evaluation, as untreated ADHD can cause social or academic challenges that can interfere with a child’s well-being.

Because adulthood comes with different expectations than childhood, symptoms of ADHD tend to manifest differently in adults. A hyperactive child, for instance, may run around the house or struggle to wait their turn in a game. A hyperactive adult, on the other hand, may feel “restless” or fidgety when sitting still; their hyperactivity may also manifest as excessive talking or frequent interruption of others. Impulsivity, similarly, may manifest in adults as impulsive financial or relationship choices, rather than impulsive physical behavior.

ADHD is diagnosed in children more often than it is in adults, though the adult diagnosis rate has increased in recent years. In the U.S., children can be diagnosed as young as 4, according to guidelines set by the American Academy of Pediatrics. They are more commonly diagnosed after they enter school, however, as symptoms tend to become more apparent and problematic then.

Whether ADHD is over- or underdiagnosed is the subject of fierce debate. The rate of ADHD diagnosis, and the use of medications to treat it, have risen dramatically over the past few decades (particularly in Western countries), leading many to argue that diagnoses and prescriptions are being given far too liberally. Many primary care doctors—who are often tasked with diagnosing and treating ADHD—receive little training on the subject and often don’t conduct an in-depth evaluation, potentially strengthening the argument that ADHD is being diagnosed inappropriately. Many also argue that the ADHD label is often put on “difficult” children in order to help their parents or teachers manage them.

The argument for overdiagnosis of ADHD is more familiar to many, but some experts argue that the disorder may in fact be underdiagnosed, particularly in those (typically women and girls) whose symptoms are subtler or less disruptive. Many adults with ADHD report that they were first diagnosed with depression or bipolar disorder but found treatment ineffective; after being evaluated for and diagnosed with ADHD, they reported significant benefits from therapies (medical or otherwise) designed specifically for ADHD. General stigma surrounding mental illness—and the common idea that ADHD is an excuse for laziness or poor parenting—may also lead many people to avoid seeking a diagnosis for fear of being labeled as slackers or bad parents.

ADHD symptoms fall into two groups: inattentive and hyperactive/impulsive. It is possible to only display symptoms from one category. Someone who only displays inattentive symptoms may be diagnosed with ADHD, inattentive-type; this type was formally called simply attention deficit disorder (or ADD), rather than attention-deficit/hyperactivity disorder, and is still known by that name to some extent. A person who only displays hyperactive symptoms, on the other hand, may be diagnosed with ADHD, hyperactive-impulsive type.

Yes. Someone who displays both inattentive and hyperactive symptoms is said to have combined type ADHD. Combined type ADHD is the disorder’s most common presentation.

Girls and women are more commonly diagnosed as having inattentive type ADHD. It is possible, however, for girls to have hyperactive type ADHD. Some experts contend that girls with hyperactive symptoms may be passed over for diagnosis because they may not engage in the same external behaviors that hyperactive boys do, and may instead manifest their hyperactivity through excessive chattiness, emotional over-reactivity, or chewing on hair or clothes. Similarly, societal expectations of how girls and boys "should" behave may mean that some girls may make an effort to suppress their hyperactivity; girls may also be more likely to be treated for depression or anxiety, rather than ADHD.

No. Though boys appear to be more likely than girls to display hyperactive or impulsive behaviors, it is possible for boys to be diagnosed with primarily inattentive type ADHD.