Let others know that there is hope and understanding. You can change the way the world sees mental health.

What is ADHD?

Attention-deficit hyperactivity disorder (ADHD) is a condition characterized by inattention, hyperactivity and impulsivity. The most commonly diagnosed behavior disorder in young people, the Center for Disease Control and Prevention (CDC) reports that ADHD affects an estimated 9 percent of children aged 3-17 and 2-4 percent of adults.

Although ADHD has its onset and is usually diagnosed in childhood, it is not a disorder limited to children—ADHD often persists into adolescence and adulthood and is frequently not diagnosed until later years.

More on ADHD:

What are the symptoms?

There are actually thought to be three different types of ADHD, each with different symptoms: predominantly inattentive, predominantly hyperactive/impulsive and combined. Diagnosing ADHD requires a comprehensive evaluation and cannot be done with one single test.There are actually thought to be three different types of ADHD, each with different symptoms: predominantly inattentive, predominantly hyperactive/impulsive and combined.

Those living with the predominantly inattentive type often:

• fail to pay close attention to details or make careless mistakes in schoolwork, work or other activities;

• have difficulty sustaining attention to tasks or leisure activities; do not seem to listen when spoken to directly;

• do not follow through on instructions and fail to finish schoolwork, chores or duties in the workplace;

• have difficulty organizing tasks and activities;

• avoid, dislike or are reluctant to engage in tasks that require sustained mental effort;

• lose things necessary for tasks or activities;

• are easily distracted by extraneous stimuli; and are forgetful in daily activities.

Those living with the predominantly hyperactive/impulsive type often:

• fidget with their hands or feet or squirm in their seat;

• leave their seat in situations in which remaining seated is expected;

• move excessively or feel restless during situations in which such behavior is inappropriate;

• have difficulty engaging in leisure activities quietly;

• are “on the go” or act as if “driven by a motor;”

• talk excessively;

• blurt out answers before questions have been completed;

• have difficulty awaiting their turn; andinterrupt or intrude on others.

Those living with the combined type, the most common type of ADHD, have a combination of the inattentive and hyperactive/impulsive symptoms.

It is also important to note that ADHD is a condition that often coexists with other conditions. Read more about ADHD and coexisting conditions.


While we don’t know for sure what causes ADHD, we do know that ADHD probably results from a combination of genetic and environmental factors. ADHD is a brain-based disorder and is strongly inherited, but parenting styles do not cause ADHD.

Genes are passed on to us from our parents and provide instruction for how our body develops and grows. Studies of twins prove that ADHD does run in families and more research is being done into what specific genes may make people more likely to develop ADHD. An NIMH research study showed that children with a certain gene have thinner brain tissue in the parts of the brain linked to attention. However, the research showed that this difference was not permanent and that as the children with this gene got older, the brain developed a normal level of thickness and their ADHD symptoms also got better.

Environmental factors found in our day-to-day lives can influence our health. Research studies have shown that there is a possible link between cigarette smoking and alcohol consumption during pregnancy and ADHD in children. Another study showed that preschoolers exposed to high levels of lead may have a higher risk of developing ADHD.


Diagnosing ADHD requires a comprehensive evaluation and cannot be done with one single test. A licensed health professional will compile information about the child’s academic, social and emotional functioning as well as rule out physical factors that could be causing symptoms similar to ADHD. Other factors such as anxiety, depression and some learning disorders may cause similar symptoms as ADHD and may coexist with ADHD.

Parents and teachers can provide an important history of the child’s behavior and when appropriate, as can the child. While the health professional will pay more attention to a child’s behavior in more structured settings, the child’s age must also be taken into account. It is important to note if the child’s behavior interferes with their day to day life and how often the behavior occurs. The Diagnostic and Statistical Manual IV is an important tool that needs to be included in the evaluation. In order to diagnose ADHD in adults, childhood history as well as current symptoms must be considered. For more information on diagnosis, visit NIMH and the National Resource Center on ADHD.

Treatment, Services and Support

A key aspect of treating ADHD is taking a “multimodal” approach. This means utilizing multiple methods for treatment including medical, educational, behavioral and psychological. Read more.

Living With ADHD

Children and Adolescents

ADHD may affect each child or youth differently, but it is important for parents to consider such areas as school, coexisting conditions and parenting strategies. 


Relationships and work are two areas that may be affected in an adult living with ADHD. Learn about legal rights related to workplace modifications and cultural issues that may affect your experience learning to cope with ADHD.