ADHD: 2015's Most Important Research

Laurie E. Scudder, DNP, NP; Paul H. Lipkin, MD; Robert L. Finding, MD


July 21, 2015

In This Article

Editor's Note:
Attention-deficit/hyperactivity disorder (ADHD) continues to receive a great deal of attention from the research community, and new findings are published weekly. But has the new evidence changed our approach to the diagnosis and management of children and adolescents with ADHD?

Medscape spoke with two experts about the current state of knowledge, what we still don't know, and what the latest research suggests about the diagnosis and management of this increasingly common disorder. Dr Paul Lipkin is associate professor of pediatrics at Johns Hopkins University School of Medicine and director of medical informatics and the Interactive Autism Network at the Kennedy Krieger Institute in Baltimore, Maryland. Dr Robert Findling is professor of psychiatry and behavioral sciences, and director of child and adolescent psychiatry at Johns Hopkins, as well as vice president of psychiatric services and research at the Kennedy Krieger Institute.

Underrecognized Groups With ADHD

Medscape: A recent data brief from the Centers for Disease Control and Prevention's (CDC's) National Center for Health Statistics[1] reported that the prevalence of ADHD varies considerably, depending on such factors as insurance status and ethnicity. Can you speak about the epidemiology of ADHD in the United States, particularly in terms of demographic and socioeconomic influences?

Dr Lipkin: Our knowledge about ADHD across time has been primarily derived from school-aged boys, in large part because that is the population used for many of the medication trials. But as interest has expanded over the years, it was obviously important to identify underrecognized populations, and the first group that drew attention was girls.

The second underrecognized group is children who are primarily inattentive and not overly hyperactive. I work in a developmental center, and we see a lot of children who are having school problems, but without frank behavior problems.

Over the past 10 years, a lot more thought, particularly from an epidemiologic perspective, has been given to ethnic and socioeconomic issues in ADHD. The CDC highlighted nicely how much we do and do not know about ADHD among underrepresented groups.

We still see a predominance of boys vs girls, and that is going to change over time. Among ethnic groups, the frequency is probably highest among African American children and lowest among Hispanic children, with white children being somewhere in between.

The numbers tend to cluster around 10% of children having ADHD, but among ethnic groups we still see differences. The question becomes how much of this is socioeconomic, how much of it has to do with means of identification, and how much has to do with treatment variables. Those questions will need answers in the coming years.

With the high rate seen in the African American population, it brings up the question about underserved children. How many children out there are receiving the kind of ADHD care that they need? Are they receiving both the medical treatment that we know can be helpful, as well as the behavioral therapeutic treatments? If you look at poor populations where those services are less available, it raises concerns about how well we are serving the broad ADHD community, if those populations don't have the right resources available.

Comorbidity in ADHD

Medscape: A new study from Johns Hopkins[2] found that children with ADHD are 12 times more likely to have binge-eating behaviors, and another study[3] found an association between ADHD and premature death. Older research has indicated a link with suicide and other psychiatric diagnoses.[4]

Can you discuss the clinical relevance of these findings? How should primary care providers be screening for these comorbid conditions? Are there other conditions that commonly occur with ADHD that clinicians should be on the lookout for? 

Dr Findling: For many reasons, thediagnosis of ADHD is not easy to make. But assuming that you are confident in your diagnosis, we have known for years that comorbid conditions are the rule and not the exception.

If you identify a child and are confident in the diagnosis of ADHD, you need to think about comorbid conditions, some of which are the result of ADHD and others with symptoms that overlap with ADHD. Binge eating is associated with impulse control. We know that people with ADHD are more impulsive than other people. Many of the features of ADHD contribute to the expression of other difficulties.

Medscape: Premature death and suicidality have an impulsive component; is that correct?

Dr Findling: Correct. We also know that people with ADHD have higher rates of mood disorders, and mood disorders are a leading risk factor for completed suicide. Being impulsive as well as depressed is not a great combination, so if a person is suicidal, impulsivity can lead to bad outcomes.

Premature death is often sudden, primarily owing to accidents. Persons who are risk-takers or who are easily distracted have more motor vehicle accidents and other types of accidents that can have consequences—not just injury, but death.

These symptoms of ADHD can affect eating behaviors, self-injurious acts when depressed, or even day-to-day life. All of these can lead to injuries and accidents and more trips to the emergency department. In more severe cases, events that are associated with risk-taking behavior or distractibility can even be lethal.

That is what we are talking about here—the characteristics of ADHD that have an impact in other domains outside of an ADHD context.

Dr Lipkin: In some ways, a diagnosis of ADHD is a red flag or a marker—the tip of the iceberg, signaling that there is a range of problems below the surface. For the primary care provider, it becomes important to recognize that this is more than just an isolated behavior disorder. It can unfold an array of medical, psychiatric, and behavioral issues across time.


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