Attention-deficit/hyperactivity disorder (ADHD)

Everybody can have difficulty sitting still, paying attention or controlling impulsive behavior once in a while. For some people, however, the problems are so pervasive and persistent that they interfere with every aspect of their life: home, academic, social and work. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder affecting 11 percent of school-age children. Symptoms continue into adulthood in more than three-quarters of cases. ADHD is characterized by developmentally inappropriate levels of inattention, impulsivity and hyperactivity. Individuals with ADHD can be very successful in life. However, without identification and proper treatment, ADHD may have serious consequences, including school failure, family stress and disruption, depression, problems with relationships, substance abuse, delinquency, accidental injuries and job failure. Early identification and treatment are extremely important. Medical science first documented children exhibiting inattentiveness, impulsivity and hyperactivity in 1902. Since that time, the disorder has been given numerous names, including minimal brain dysfunction, hyperkinetic reaction of childhood, and attention-deficit disorder with or without hyperactivity. With the Diagnostic and Statistical Manual, Fifth Edition (DSM-5) classification system, the disorder has been renamed attention-deficit/hyperactivity disorder or ADHD. The current name reflects the importance of the inattention aspect of the disorder as well as the other characteristics of the disorder such as hyperactivity and impulsivity.

Symptoms:

The DSM-5 lists three presentations of ADHD—Predominantly Inattentive, Hyperactive-Impulsive and Combined. The symptoms for each are adapted and summarized below. ADHD predominantly inattentive presentation Fails to give close attention to details or makes careless mistakes Has difficulty sustaining attention Does not appear to listen Struggles to follow through with instructions Has difficulty with organization Avoids or dislikes tasks requiring sustained mental effort Loses things Is easily distracted Is forgetful in daily activities ADHD predominantly hyperactive-impulsive presentation Fidgets with hands or feet or squirms in chair Has difficulty remaining seated Runs about or climbs excessively in children; extreme restlessness in adults Difficulty engaging in activities quietly Acts as if driven by a motor; adults will often feel inside as if they are driven by a motor Talks excessively Blurts out answers before questions have been completed Difficulty waiting or taking turns Interrupts or intrudes upon others ADHD combined presentation The individual meets the criteria for both inattention and hyperactive-impulsive ADHD presentations. These symptoms can change over time, so children may fit different presentations as they get older.

Causes: Despite multiple studies, researchers have yet to determine the exact causes of ADHD. However, scientists have discovered a strong genetic link since ADHD can run in families. More than 20 genetic studies have shown evidence that ADHD is strongly inherited. Yet ADHD is a complex disorder, which is the result of multiple interacting genes.