Attention Deficit Hyperactivity Disorder (ADHD or AD/HD) is a neurobehavioral developmental disorder. ADHD is primarily characterized by "the co-existence of attentional problems and hyperactivity, with each behavior occurring infrequently alone."
ADHD is the most commonly studied and diagnosed psychiatric disorder in children, affecting about 3 to 5% of children globally with symptoms starting before seven years of age. ADHD is a common chronic disorder in children with 30 to 50% of those individuals diagnosed in childhood continuing to have symptoms into adulthood. Adolescents and adults with ADHD tend to develop coping mechanisms to compensate for some or all of their impairments.
Though previously regarded as a childhood diagnosis, ADHD can continue throughout adulthood. ADHD is diagnosed two to four times as frequently in boys as in girls, though studies suggest this discrepancy may be due to subjective bias of referring teachers. Its symptoms can be difficult to differentiate from other disorders, increasing the likelihood that the diagnosis of ADHD will be missed or vice versa. Additionally, most clinicians have not received formal training in the assessment and treatment of ADHD, particularly in adult patients.
Inattention, hyperactivity, and impulsivity are the key behaviors of ADHD. The symptoms of ADHD are especially difficult to define because it is hard to draw the line at where normal levels of inattention, hyperactivity, and impulsivity end and clinically significant levels requiring intervention begin. To be diagnosed with ADHD, symptoms must be observed in two different settings for six months or more and to a degree that is greater than other children of the same age.
The symptom categories of ADHD in children yield three potential classifications of ADHD—predominantly inattentive type, predominantly hyperactive-impulsive type, or combined type if criteria for both subtypes are met:
Predominantly inattentive type symptoms may include:
- Be easily distracted, miss details, forget things, and frequently switch from one activity to another.
- Have difficulty focusing on one thing.
- Become bored with a task after only a few minutes, unless they are doing something enjoyable.
- Have difficulty focusing attention on organizing and completing a task or learning something new.