Post by Former NIMH Director Thomas Insel: Attention on ADHD Awareness Week
September 12-18 is ADHD Awareness Week, a good time to reflect on progress and directions for future studies of attention deficit hyperactivity disorder (ADHD).
ADHD is one of the most common childhood disorders, affecting nearly 5 percent of school-age children, with symptoms such as difficulty staying focused and paying attention, difficulty controlling behavior, and hyperactivity. Stimulant medications can help reduce the frequency or severity of ADHD symptoms for many people. For some, however, these medications provide little to no benefit. Like all medications, stimulants also carry the risk of side effects. In rare cases, the side effects of stimulants may be serious, such as raising blood pressure and heart rate. Finding new or better ways to treat ADHD is a central focus to many NIMH-funded studies.
Large-scale clinical trials, such as the Multimodal Treatment Study of Children with ADHD (MTA) and Preschoolers with ADHD Treatment Study (PATS), have provided important clues about what makes treatment work, or not work, for different individuals. For example, some findings suggest that:
- Using low dose methylphenidate (for example, Ritalin) can be effective for treating severe ADHD in children ages 3–5 years old.
- Having fewer coexisting disorders has been linked with better treatment response to stimulant medications. Children with three or more coexisting disorders tend not to respond to stimulant treatment.
- Maintaining a good treatment response as a child with ADHD matures and adapts to the demands of adolescence is likely to require a sustained effort that takes into account long-term academic and behavioral problems commonly associated with the disorder.
Having effective methods for reducing core symptoms of ADHD can mean the difference between a child excelling at school or missing class due to inattention or disruptive behavior. But not all children respond well to currently available medications. Fortunately, some early behavioral interventions designed to reduce symptoms of ADHD in preschoolers may be effective alternatives or additions to medication treatment. Researchers are currently exploring a number of creative treatment approaches as well, such as nonstimulant medications, EEG biofeedback, and novel psychosocial therapies.
The long-term consequences for work performance and social relationships in adulthood create a sense of urgency to identify ADHD and intervene as early as possible. Understanding the factors that contribute to better or poorer outcomes, and which treatments work best for which individuals, requires a more complete understanding of how the trajectories of brain development can differ in ADHD. For instance, a series of studies at NIMH studied one aspect of brain development: changes in cortical thickness in different regions of the brain across child development. In typical development, there is a pattern of increasing, and then decreasing, cortical thickness. Brain imaging in children with ADHD revealed that brain development followed the same pattern of increasing and then decreasing thickness, but the trajectory was delayed by an average of three years in some regions. Furthermore, these trajectories of brain development varied widely for children with ADHD, and the timing of delays was related to severity of symptoms. While cortical thickness is only one aspect of brain development, these findings illustrate that it is possible to correlate behaviors with brain differences, and may lead to improved treatments based on individual differences in symptom expression or biological characteristics. Other current studies of ADHD are revealing which neurotransmitters are affected by ADHD and which genes are correlated with ADHD symptoms and brain dysfunction. The results of these studies may reveal new approaches to treatment.
While ADHD most often affects young children, the disorder can continue through adolescence. The impulsivity of ADHD can pose particular challenges for teens, leading to increased involvement in risky behaviors. Teenagers with ADHD get 3 times as many speeding tickets and are 4 times more likely to be involved in a car accident than their non-ADHD peers. ADHD can sometimes persist into adulthood. More studies are needed to assess the effects of ADHD over the lifespan and to find better ways to diagnose and treat the disorder in adults, with a special attention to promoting competence and improving functioning.
In addition to supporting research, NIMH also seeks to raise public awareness of mental illnesses. Learning about disorders like ADHD can make it easier to recognize when you or someone close to you needs help and to seek appropriate treatment.