Attention-deficit/hyperactivity disorder (ADHD) is marked by an ongoing pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development. People with ADHD experience an ongoing pattern of the following types of symptoms:
Signs and Symptoms
Some people with ADHD mainly have symptoms of inattention. Others mostly have symptoms of hyperactivity-impulsivity. Some people have both types of symptoms.
Many people experience some inattention, unfocused motor activity, and impulsivity, but for people with ADHD, these behaviors:
People with symptoms of inattention may often:
People with symptoms of hyperactivity-impulsivity may often:
Primary care providers sometimes diagnose and treat ADHD. They may also refer individuals to a mental health professional, such as a psychiatrist or clinical psychologist, who can do a thorough evaluation and make an ADHD diagnosis.
For a person to receive a diagnosis of ADHD, the symptoms of inattention and/or hyperactivity-impulsivity must be chronic or long-lasting, impair the person’s functioning, and cause the person to fall behind typical development for their age. Stress, sleep disorders, anxiety, depression, and other physical conditions or illnesses can cause similar symptoms to those of ADHD. Therefore, a thorough evaluation is necessary to determine the cause of the symptoms.
Most children with ADHD receive a diagnosis during the elementary school years. For an adolescent or adult to receive a diagnosis of ADHD, the symptoms need to have been present before age 12.
ADHD symptoms can appear as early as between the ages of 3 and 6 and can continue through adolescence and adulthood. Symptoms of ADHD can be mistaken for emotional or disciplinary problems or missed entirely in children who primarily have symptoms of inattention, leading to a delay in diagnosis. Adults with undiagnosed ADHD may have a history of poor academic performance, problems at work, or difficult or failed relationships.
ADHD symptoms can change over time as a person ages. In young children with ADHD, hyperactivity-impulsivity is the most predominant symptom. As a child reaches elementary school, the symptom of inattention may become more prominent and cause the child to struggle academically. In adolescence, hyperactivity seems to lessen and symptoms may more likely include feelings of restlessness or fidgeting, but inattention and impulsivity may remain. Many adolescents with ADHD also struggle with relationships and antisocial behaviors. Inattention, restlessness, and impulsivity tend to persist into adulthood.
Researchers are not sure what causes ADHD, although many studies suggest that genes play a large role. Like many other disorders, ADHD probably results from a combination of factors. In addition to genetics, researchers are looking at possible environmental factors that might raise the risk of developing ADHD and are studying how brain injuries, nutrition, and social environments might play a role in ADHD.
ADHD is more common in males than females, and females with ADHD are more likely to primarily have inattention symptoms. People with ADHD often have other conditions, such as learning disabilities, anxiety disorder, conduct disorder, depression, and substance use disorder.