ADHD: Key Q&A

What is ADHD?

ADHD is an acronym for attention deficit hyperactivity disorder. This is a set of chronic conditions marked by an inability to pay attention, hyperactivity and impulsive acts. It begins in childhood and can affect all areas of a child's life. In recent years, the National Institute of Mental Health has declared definitively that ADHD is a mental health condition.

How common is ADHD?

Between 3 and 5 percent of school-aged children - or about 2 million children in the United States - have ADHD, according to the National Institute of Mental Health. Boys outnumber girls by at least a three to one ratio, according to National Mental Health Association. About 80 percent of children who take medications for their ADHD continue to need the drugs during their teen years, according to the National Institute of Mental Health.

Do head injuries or poor parenting cause ADHD?

No. Earlier theories suggested that minor head injuries or brain damage caused by infections or birthing complications might be responsible for ADHD. However, experts have not found evidence to support this hypothesis. Theories that too much or too little sugar may cause ADHD also appear to be unfounded.

Poor parenting skills do not cause a child's ADHD. Nonetheless, problems in the home or difficulties in school or community environments can exacerbate ADHD.

What types of medications may be prescribed for ADHD?

The three major categories of drugs used to treat ADHD are psychostimulants, alpha-2 adrenergic agonists and antidepressants.

Psychostimulants, more commonly referred to as simply "stimulants," inhibit the reabsorption of dopamine. Dopamine is a neurotransmitter that helps to keep the central nervous system functioning normally. This leaves more dopamine circulating in the body. Stimulants are the mainstay of ADHD medication treatment, and up to 90 percent of people who take them report at least some improvement in symptoms like impulsivity and hyperactivity, according to the American Psychiatric Association. Although these drugs have a stimulating effect on most people, they are calming in those with ADHD.

Stimulants usually work fairly rapidly, with symptom reduction beginning between 30 and 45 minutes after ingestion. They work for between four and 12 hours and are typically taken two to three times daily. Some longer-acting formulations, known as extended release versions, may be taken just once a day. Most of the stimulants are only recommended for children over age 6. However, some amphetamines may be prescribed to children over age 3. The stimulant pemoline, which was once prescribed for ADHD, was withdrawn from the market in 2005 because it may cause serious side effects, including liver damage.

Alpha-2 adrenergic agonists are sometimes used to treat core ADHD symptoms, but more often are used to reduce irritability and aggression and to treat body tics related to ADHD. They can also be used to promote sleep in people who report insomnia.

Depression is a disorder commonly associated with ADHD, and antidepressants are often prescribed to treat lasting feelings of sadness. In addition, antidepressants that increase the availability of the neurotransmitters dopamine, and norepinephrine and serotonin in the body appear to be effective in treating core symptoms of ADHD.

The norepinephrine specific reuptake inhibitor, or NSRI, atomoxetine is particularly effective in treating ADHD.

Antidepressants are sometimes used to treat ADHD in patients who do not tolerate stimulants well. These drugs only have to be taken once daily. Selective serotonin reuptake inhibitors, or SSRIs, which are often used to treat depression and anxiety, have not been effective in treating the symptoms of ADHD.