Research for ADHD

Researchers have been studying what might cause ADHD. The condition tends to run in families, but experts believe many complex factors may play a role.

Studies suggest that some aspects of brain development can be delayed by 2 or 3 years in kids with ADHD, especially in the parts of the brain involved in thinking, planning, and paying attention. For many kids, Vitiello says, the brain later develops normally and these kids catch up, even though some symptoms may continue throughout their lives.

Source: NIH News in Health (NIH)1

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ADHD Research

The expansion of knowledge in genetics, brain imaging, and behavioral research is leading to a better understanding of the causes of ADHD, how to prevent it, and how to develop more effective treatments for all age groups.

Source: MedLinePlus Magazine (NIH)2

Treatment Research for ADHD

The Journal of Pediatrics has published a new study, Treatment of Attention-Deficit/Hyperactivity Disorder among Children with Special Health Care Needs, describing parent-reported treatment of ADHD among children with special health care needs, and how this reported treatment aligns with the current American Academy of Pediatrics (AAP) guidelines. This is the first nationally-representative US study on ADHD treatment that considers medication, behavioral therapy, and dietary supplements. These data on ADHD treatment were collected just before the release of the current AAP medical practice guidelines, so this information can be used as a benchmark for the state of medical practice at the time that the guidelines were published.

CDC researchers looked at data from a national sample of children with special health care needs, ages 4-17 years, collected in 2009-10. They found that just before the release of the 2011 guidelines, most children with ADHD received either medication treatment or behavioral therapy; however, many were not receiving treatment as outlined in the 2011 best practice guidelines. Current AAP guidelines[640 KB] recommend that for school-aged children (6-18 years of age) with ADHD, treatment include ADHD medication with or without behavioral therapy, with both medication and behavioral therapy as the preferred treatment. Behavioral therapy is recommended first for preschoolers (4-5 years of age) with ADHD.1

This is important information for healthcare providers so that they can gain a greater understanding of the patterns of treatment for ADHD, and what more may need to be done to improve the quality of care for children with ADHD.

Source: CDC Features3

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How treatment patterns in 2009-10 compare with current (2011) American Academy of Pediatrics' recommendations

  • Less than 1 in 3 children with ADHD received both medication treatment and behavioral therapy, the preferred treatment approach for children ages 6 and older.
  • Only half of preschoolers (4-5 years of age) with ADHD received behavioral therapy, which is now the recommended first-line treatment for this group.
  • About half of preschoolers with ADHD were taking medication for ADHD, and about 1 in 4 were treated only with medication.

State estimates of ADHD treatment among 4-17 year olds

  • Medication treatment among children with ADHD ranged from a low of 57% in California to a high of 88% in Michigan.
  • Behavioral therapy among children with ADHD ranged from a low of 33% in Tennessee to 61% in Hawaii.
  • Overall, states with higher behavioral therapy rates generally had lower medication treatment rates and vice versa. An overview of ADHD data, including maps, is here. State by state data are available here.

Conclusions and implications of this study

  • At the time the current guidelines were released, treatment patterns were different from recommendations.
  • Increasing rates of behavioral therapy among preschool-aged children with ADHD would increase the alignment of current practice and existing medical guidelines (best practice) for ADHD, and could improve the quality of care for children with ADHD.
  • More recent data are needed to understand if the treatment patterns have become more aligned with the current medical practice guidelines. Future research and policy evaluation can help determine the factors and strategies that impact state rates of behavioral therapy among children with ADHD.
  • Parents should be aware that there are recommendations for pediatric ADHD treatment and should seek care from an experienced provider.
  • Healthcare providers should be aware of psychological resources in their community so that they are prepared to refer children, particularly preschoolers, for behavioral therapy as recommended by the American Academy of Pediatrics.

Source: CDC Features4

Research for ADHD

Guanfacine: The researchers are now planning clinical studies of a drug called guanfacine, which is similar to clonidine but appears to cause less sedation, to see if it has the same beneficial effects as clonidine for these children. They also plan to test longer-acting versions of methylphenidate and other types of stimulants, such as dextroamphetamine (Dexedrine) and a combination of amphetamines (Adderall), to see what effect those drugs have on tics in children with ADHD.

Reference: The Tourette's Syndrome Study Group. "Treatment of ADHD in children with tics." Neurology, Vol. 58, No. 4, February 26, 2002, pp. 527-536.

Source: NINDS (NIH)5

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Methylphenidate: NIMH-funded researchers studied ADHD treatments for school-aged children in a large-scale, long-term study called the Multimodal Treatment Study of Children with ADHD (MTA study). Though the study has been completed, a recent follow-up found that, over a 10-year period, children with ADHD who were treated with methylphenidate had, on average, higher heart rates compared to children who received other treatments. That this effect on heart rate could be detected even after years of use, suggests that the body does not get completely used to stimulants. Children taking stimulants over the long-term should be monitored regularly for potential cardiovascular complications.

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Methylphenidate: NIMH also funded the Preschoolers with ADHD Treatment Study (PATS), which involved more than 300 preschoolers who had been diagnosed with ADHD. The study found that low doses of the stimulant methylphenidate are safe and effective for preschoolers. Preschoolers diagnosed with ADHD are less likely to respond to methylphenidate treatment if they also have three or more coexisting disorders, highlighting the need for new and better treatments.

Causal Research for ADHD

Brain imaging studies have shed some light on how ADHD unfolds. Development in some regions of the brain is delayed by an average of 3 years—and up to 6—in kids with ADHD. This delay is most marked in an area involved in focusing attention, working for reward and planning, among other things. In most kids, this part of the brain—the frontal cortex—is fully developed by the age of 7 or 8. For kids with ADHD, it’s between 10 and 13.

“That delay is carried forward into adolescence,” Shaw says. “We know that changes in brain structure and function can often persist into teenage years and beyond in people who have ADHD.”

Research has yielded insight into the brain chemistry of ADHD as well. One of the main brain chemicals that seems to be disrupted is dopamine. The chief class of medications used to treat ADHD, called psychostimulants, apparently act by boosting the levels of dopamine in the brain. Other brain chemicals have also been tied to ADHD, and new medications to target them are becoming available. What these chemicals have in common is that brain cells use them to communicate with each other.

Researchers are now using brain imaging to compare the brains of adults who recover from ADHD with those who never grew out of it. “We’re trying to understand why ADHD has such a variable outcome,” Shaw says. “If you take 100 children with ADHD and look at how they’re doing when they’re adults, some are completely better, some are essentially unchanged and a large chunk are somewhere in the middle. We’re looking at the brain basis for that variable outcome.”

Scientists also continue to seek the root causes of ADHD. They’re looking into many other aspects of ADHD as well, like how treatments in childhood affect long-term outcomes. Other researchers are trying to relate genetic differences to how the brain develops in ADHD. The ultimate goal, of course, is to find better ways to diagnose and treat the disorder.

Source: NIH News in Health (NIH)6

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NIMH-sponsored scientists continue to look for the biological basis of ADHD, and how differences in genes and brain structure and function may combine with life experiences to produce the disorder.

Source: MedLinePlus Magazine (NIH)7

Causal Research for ADHD

Brain Imaging: Brain Imaging Studies Reveal Clues to ADHD

Attention deficit hyperactivity disorder (ADHD) is one of the most common childhood brain disorders and can continue through adolescence and adulthood. Symptoms include difficulty staying focused and paying attention, difficulty controlling behavior, and hyperactivity (over-activity). These symptoms can make it difficult for a child with ADHD to succeed in school, get along with other children or adults, or finish tasks at home.

Brain imaging studies have revealed that, in youths with ADHD, the brain matures in a normal pattern but is delayed, on average, by about three years. The delay is most pronounced in brain regions involved in thinking, paying attention, and planning. More recent studies have found that the outermost layer of the brain, the cortex, shows delayed maturity overall. Studies also reveal that brain structure important for proper communications between the two halves of the brain shows an abnormal growth pattern. These delays and abnormalities may underlie the hallmark symptoms of ADHD and help to explain how the disorder may develop.

Treatments can relieve many symptoms of ADHD, but there is currently no cure for the disorder. With treatment, most people with ADHD can be successful in school and lead productive lives. Researchers are developing more effective treatments and interventions, and using new tools such as brain imaging, to better understand ADHD and to find more effective ways to treat and prevent it.

The National Institute of Mental Health (NIMH) is the National Institutes of Health's (NIH) lead agency in the research on ADHD.

Source: MedLinePlus Magazine (NIH)8

Clinical Trials for ADHD

Join a Study

Clinical trials are research studies that look at new ways to prevent, detect, or treat diseases and conditions, including ADHD. During clinical trials, investigated treatments might be new drugs or new combinations of drugs, new surgical procedures or devices, or new ways to use existing treatments. In many trials, some participants are randomly assigned to the “control” group and receive an inactive “placebo” treatment or a standard intervention currently in use; sometimes the control subjects are later given a chance to try the experimental treatment. The object is to be able to compare the effect of the experimental treatment with standard or no treatment. The goal of clinical trials is to determine if a new test or treatment works and is safe. Although individual participants may benefit from being part of a clinical trial, participants should be aware that the primary purpose of a clinical trial is to gain new scientific knowledge so that others may be better helped in the future.

Please Note: Decisions whether to apply for a clinical trial, and which ones are best suited for a given individual, are best made in collaboration with your licensed health professional.

Clinical Trials at NIMH/NIH

Scientists at the NIMH campus conduct research on numerous areas of study, including cognition, genetics, epidemiology, brain imaging, and treatment development. The studies take place at the NIH Clinical Center in Bethesda, Maryland, and require regular visits. After the initial phone interview, you will come to an appointment at the clinic and meet with a clinician. Visit the NIMH Clinical Trials — Participants or Join a Study for more information.

How Do I Find a Clinical Trial Near Me?

To find a clinical trial near you, visit ?. This is a searchable registry and results database of federally and privately supported clinical trials conducted in the United States and around the world. gives you information about a trial's purpose, who may participate, locations, and phone numbers for more details. This information should be used in conjunction with advice from health professionals.

For more information about clinical trials, visit NIH Clinical Trials and You ?.

Source: NIMH (NIH)9

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  1. Source: NIH News in Health (NIH): issue/ sep2014/ feature2
  2. Source: MedLinePlus Magazine (NIH): magazine/ issues/ spring14/ articles/ spring14pg19.html
  3. Source: CDC Features: features/ adhd-key-findings/ index.html
  4. ibid.
  5. Source: NINDS (NIH): news_and_events/ news_articles/ news_article_adhd.htm
  6. Source: NIH News in Health (NIH): 2008/ November/ feature1.htm
  7. Source: MedLinePlus Magazine (NIH): magazine/ issues/ spring14/ articles/ spring14pg19.html
  8. Source: MedLinePlus Magazine (NIH): magazine/ issues/ spring14/ articles/ spring14pg15-16.html
  9. Source: NIMH (NIH): health/ topics/ attention-deficit-hyperactivity-disorder-adhd/ index.shtml

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Note: This site is for informational purposes only and is not medical advice. See your doctor or other qualified medical professional for all your medical needs.