National Institutes of Health 

Attention Deficit Hyperactivity Disorder Fact Sheet (ADHD) 

Attention deficit/hyperactivity disorder (ADHD) is one of the most common childhood disorders and can continue into 

adolescence and adulthood. Symptoms include difficulty staying focused and paying attention, difficulty controlling 

behavior, and very high levels of activity. Studies show that the number of children being diagnosed with ADHD is 

increasing. 

Yesterday 

•	 ADHD was once considered a transient disorder of 

childhood that children would outgrow upon 

entering their teen years. 

•	 ADHD was seen as a behavioral disturbance caused 

by environmental factors, such as inconsistent 

parenting. 

•	 Brain development in people with ADHD could not 

be studied directly, but only estimated by observing 

behavior or using other indirect methods. 

•	 ADHD was treated with immediate release 

stimulant medications such as methylphenidate (for 

example, Ritalin), which worked well but whose 

effect lasted only a few hours. Children needed 

multiple doses during the day, disrupting their 

school schedules and daily activities. 

Today 

•	 Using brain imaging, scientists observed that in 

some young people with ADHD the development of 

the brain, while still showing a normal pattern, is 

delayed in some regions by an average of three 

years compared to children without the disorder. 

•	 The delay was most marked in the brain area that 

supports the ability to suppress inappropriate 

actions and thoughts, focus attention, remember 

things moment to moment, work for reward, and 

plan (the frontal cortex). By contrast, the area that 

controls movement (the motor cortex) tends to 

mature faster than normal, an exception to the 

pattern of delay. This mismatch in brain 

development may account for the restlessness and 

National Institutes of Health 

January 2009 

fidgety symptoms common among those with 

ADHD. 

•	 Findings from the Preschoolers with ADHD 

Treatment Study (PATS) indicate that using low 

dose methylphenidate (for example, Ritalin) to treat 

children age 3–5 years diagnosed with severe 

ADHD can be effective. 

•	 A preschooler’s response to medications for ADHD 

has been found to be associated with the number of 

coexisting mental disorders the child has. Children 

with fewer coexisting disorders were most likely to 

respond to methylphenidate treatment, whereas 

those with three or more coexisting disorders did 

not respond to the treatment. 

•	 For some children, early behavioral interventions 

designed to reduce symptoms of ADHD in 

preschoolers may be effective alternatives or 

additions to medication treatment. 

•	 One study comparing a parent education (PE) 

program with a multi-component intervention 

(MCI) found that problem behavior decreased 

among the children in both programs and their 

social skills improved after one year. 

•	 The PE program focused on teaching parenting 

skills in a group setting. The MCI included parent 

education classes as well as individualized 

interventions in the home and at preschool or day 

care. 

•	 The ongoing Multimodal Treatment Study of 

Children with ADHD (MTA study) is helping to 

inform long-term treatment decisions. For example, 

Attention Deficit Hyperactivity Disorder – 1 
MTA researchers found that medication works best 

when treatment is regularly monitored by the 

prescribing doctor and the dose is adjusted based on 

the child’s needs. Two years after the study ended, 

most children treated in a variety of ways for 

ADHD showed sustained improvement. 

Tomorrow 

•	 Research continues on the search for innovative 

methods to treat ADHD and may someday offer 

more options for children who cannot take ADHD 

medications or do not respond to them. These 

methods include using neurofeedback and novel 

psychosocial treatments. 

•	 During neurofeedback, a person uses information 

(feedback) about his or her brain waves to try to 

bring those waves into a range associated with 

healthy brain function. NIH-funded researchers are 

testing whether children with ADHD could learn to 

respond to neurofeedback and change their brain 

wave patterns in a way that would improve 

behavior. The research uses a new technology to 

provide neurofeedback in which a child’s brain 

waves control a video game. In the test group, 

changes in brain waves will change the action 

occurring in the video game, while in the control 

group, pre-programmed changes will occur, 

independent of changes in the child’s brain waves. 

•	 Another study is focusing on treating children with 

ADHD and impaired mood (AIM), which bears 

some resemblance to bipolar disorder. Treatment 

for AIM can be complicated because the symptoms 

straddle two mental disorders that are usually 

treated with very different medications. Currently, it 

is unclear how children with AIM will respond to 

treatment with stimulants or whether medications 

used for bipolar disorder are appropriate as initial 

treatment. Researchers are evaluating a new 

psychosocial treatment that combines several 

different therapeutic approaches to see whether the 

treatment is safe for children with AIM. They are 

also trying to identify a safe and effective initial 

treatment for AIM as well as evaluating the safety 

of stimulant medications in these children. 

•	 While ADHD symptoms may decline for some 

children as they grow up, others may face 

continuing problems. A recent study found that 

adults with ADHD have higher than average rates 

of divorce, unemployment, substance abuse, and 

disability. Also, while many adults with ADHD 

receive treatment for other mental disorders or 

substance abuse, a smaller proportion receive 

treatment for their ADHD symptoms. 

•	 More studies are needed to assess the effects of 

ADHD over the lifespan and to find better ways to 

diagnose and treat ADHD in adults, with a special 

focus on promoting competence and improving 

functioning. 

•	 New research linking genetics, brain development, 

and functioning are providing scientists with a new 

understanding of how ADHD develops. 

•	 One such study showed that brain areas controlling 

attention were thinnest in children with ADHD who 

carried a particular version of the gene for one type 

of neuro-chemical receptor in the brain. However, 

these areas normalized in thickness during the teen 

years in these children, coinciding with clinical 

improvement. Although this particular gene version 

increased risk for ADHD, it also predicted better 

clinical outcomes and higher IQ than two other 

versions of the same gene in youth with ADHD. 

Composite 3-D MRI scan data for youth, ages 8-16. 

Colored areas are those in which cortex thickness 

varied between ADHD study participants and healthy 

controls, with brighter colors indicating greater 

differences. 

Children with ADHD with a certain version of the 

dopamine receptor gene had thinner-than-normal areas 

in their brain’s outer mantle, the cerebral cortex, which 

normalized during the teen years. This thickening in 

areas that control attention paralleled clinical 

improvement. 

Source: NIMH Child Psychiatry Branch 

For more information, please contact the NIMH 

Information Center at nimhinfo@nih.gov or 

301-443-4513. 

National Institutes of Health Attention Deficit Hyperactivity Disorder – 2 

January 2009