Attention-Deficit/Hyperactivity Disorder:
A Public Health Research Agenda
Lesesne, C., Abramowitz,
A., Perou, R., & Brann, E. Attention deficit/hyperactivity disorder:
A public health research agenda. [2000, March 15]
Attention-Deficit/Hyperactivity Disorder (ADHD) is a serious public
health problem because of the large estimated prevalence1
of the disorder; significant impairment in the areas of school
performance and socialization; the chronicity of the disorder; the
limited effectiveness of current interventions to attend to all the
impairments associated with ADHD; and the inability to demonstrate that
intervention provides substantial benefits for long-term outcomes.
However, because of the evolution of the case definition and differences
in how the case definition is operationalized, there is disagreement as
to prevalence and precise characteristics of children with the disorder.
Because of the lack of a single,
consistent, and standard research protocol for case identification,
variable and disparate findings have been noted in the literature.
Consequently, relatively little is known about the etiology of ADHD,
although genetic factors are believed to be important contributors. The
basic epidemiology of ADHD needs further research to include the basic
prevalence and identification of risk factors for ADHD.
The Division of Birth Defects, Child
Development, and Disability and Health (proposed) hosted a conference
September 23-24, 1999, entitled, "Attention Deficit Hyperactivity
Disorder: A Public Health Perspective". The meeting gathered over 150
individuals from a variety of research, consumer, academic, medical, and
mental health disciplines to discuss the public health issues related to
this disorder and potential future research. The conference
presentations and material from the breakout sessions have been used to
help prepare a public health research agenda for ADHD. This document
delineates that plan.
Public health issues in ADHD can be
divided into three areas: the burden of ADHD in the population,
epidemiologic research issues in ADHD, and concerns related to
interventions for ADHD. These three topical areas were identified by CDC
as crucial for examining ADHD, and necessary to address public health
concerns and opportunities for action. The Division of Birth Defects,
Child Development, and Disability and Health (proposed) has used the
information and suggestions from the conference and highlighted the key
issues for each topic as well as the necessary actions to address these
public health needs. The formal topical areas are:
Social and Economic Burden of ADHD through the Lifespan
Issues
Given the nature of the disorder,
ADHD is believed to have a noticeable impact on social, economic,
educational, and health care delivery systems. Additionally, it is
reasonable to assume the condition affects those socially associated
with an ADHD individual, including his/her family members, peers, and
co-workers. However, the magnitude of the social and economic burden in
these areas has not been systematically documented.
In general, small, clinic-based
studies have shown that adults with ADHD consistently exhibit problems
with interpersonal relationships, often have difficulty with employment,
and frequently have comorbid or secondary conditions that further
debilitate. Perhaps many of the disabilities and poorer outcomes
associated with ADHD actually are more strongly associated with
conditions that are highly comorbid with ADHD (such as Conduct Disorder)
and result in significantly higher economic consequences to society.
However, this hypothesis has not been tested.
In understanding the full nature of
the disorder, it is imperative to understand the effect it has on the
families of children with ADHD. These families may be more prone to
conflict and increased levels of familial stress. The child with ADHD
may also reduce the parents' productive participation in activities
outside the family (work and community life). Many parents of children
with ADHD themselves have the disorder or considerable levels of the
symptomatology. However, the impact this disorder has on the family unit
and in adult life needs considerable research effort to clarify what
aspects of family it impacts and in what ways.
In addition, there is little concrete
knowledge of the degree to which interventions can or do improve the
outcome of children with ADHD. Developing ways to improve outcomes must
begin with consistent and standardized measures of the impact of the
disorder. Such methodical surveying has not occurred. Development of
standardized burden measures is critical to beginning this process.
Action to Address Public Health Needs
-
Conduct analyses of ADHD public
health burden in a way that estimates a broad array of costs outside
of those exclusively associated with medical treatment. The burden
should be studied from a broad perspective to include estimations of
cost to society in a monetary sense as well as to individual-level
indicators of well-being such as family functioning and social
relationships.
-
Develop a standardized way to
measure burden associated with ADHD and promote its use across
studies. This would enable cross-study comparisons such as
meta-analysis to be undertaken. This standardized measure should
account for medical/treatment costs, educational costs, family costs,
and adult functioning variables.
-
Incorporate information on ADHD in
efforts to study and prevent unintentional injuries, alcohol and drug
abuse, sexual risk-taking, disability, and other health risk behaviors
in which ADHD may play an important role.
-
Include standardized measurements
of burden in all public health research of ADHD. Future efforts to
measure the impact of ADHD across a cohort should be a priority.
Understanding if current interventions or future prevention strategies
result in burden reduction will depend largely on consistent and
accurate estimation of these burdens.
-
Efforts must be made to estimate
the prevalence and cost of this disorder in adult populations to
understand the strict monetary costs as well as to better understand
the areas of impairment for adults with ADHD.
-
Conduct population-based ADHD
research that includes information on comorbid conditions and the
burden with which they are associated. Much of our current evidence
regarding comorbid conditions comes from clinical studies rather than
population-based studies.
-
Explore mechanisms to append
economic and social burden studies on other ongoing or completed
studies in order to quantify the burden of ADHD.
-
Foster collaborations across
Federal agencies in order to include information on ADHD in data
collection efforts.
-
Establish a resource for both
professionals and the public regarding what is known about the impact
of ADHD.
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Epidemiologic Issues in ADHD
Issues
Although investigation of ADHD has
been quite extensive over the past 30 years, the scientific process has
been significantly slowed by the lack of a single, consistent, and
standard research protocol for case identification. Variable and
disparate findings have been noted throughout the literature even on
basic issues such as prevalence. As a consequence, speculation regarding
possible increases in ADHD prevalence cannot currently be evaluated.
Additionally, we do not have
demographic and descriptive statistics for children and adults with the
disorder; therefore, there are disparities in identification, access to
treatment, and reports of the manifestation of ADHD and its
comorbidities. Risk factors for ADHD have not been thoroughly
investigated although some clinical samples have identified possible
factors that may contribute to ADHD. Some of these related factors are
prenatal alcohol use, prenatal smoking, and low birth weight. Genetic
predisposition or family history of ADHD has been noted consistently
among clinical samples as a risk factor for the development of ADHD.
Unfortunately, many fundamental
etiologic questions remain for ADHD. Identifying and understanding
etiologic factors will enhance prevention efforts and treatment for both
children and adults with ADHD.
Action to Address Public Health Needs
-
Develop standard case
identification protocols for use in research projects.
-
Conduct etiologic studies of ADHD
using population-based approaches to identify important risk factors
and opportunities for prevention activities and research.
-
Use observational epidemiologic
methods to describe the impact of ADHD, its impact, and its
intervention patterns at the population level.
-
Utilize scientific findings to
develop, design, and implement ADHD prevention efforts where possible.
-
Identify current national or
regional surveys where adding ADHD questions would provide
particularly useful information regarding the magnitude of the
disorder, the nature of common comorbidity and/or secondary
conditions, as well as data on health risk behaviors and long-term
outcomes for those with ADHD.
-
Establish a Federal interagency
workgroup to pool research expertise and resources in order to launch
epidemiologic research efforts that address the public health research
needs in ADHD. Such collaborations should be multi-disciplinary and
include professionals in epidemiology, mental/physical health, risk
behavior prevention, and health communication for example.
-
Establish a resource for both
professionals and the public regarding what is known about the
epidemiology of ADHD.
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Interventions for ADHD
Issues
ADHD is a chronic condition of high
prevalence that requires long-term intervention. Because ADHD is an
impairing condition and can have lifelong consequences, interventions
designed to reduce negative outcomes and increase capacities should be
carefully considered at the national level. One key public health
concern is the safety of pharmacological interventions. A second key
concern is the effectiveness of current interventions to reduce the
impairment associated with ADHD thereby improving health and functioning
for ADHD individuals over time. A third public health concern is access
to appropriate interventions for individuals and families affected by
the disorder.
There are several public health
concerns relative to pharmacotherapy. Pharmacologic treatment is
extremely prevalent. Assessing the health risks and benefits to young
children, particularly preschoolers, is a high priority. Children who
begin medication therapies very early and receive treatment on a
long-term basis may have unknown risks associated with current
treatments. Additionally, pharmacologic interventions often do not
normalize behavior. Research, albeit limited, suggests that even with
long-term treatment, children and adults with ADHD experience
substantial problems in the school, home, workplace, and community
settings. This raises questions about the effectiveness of pharmacologic
interventions as a long-term approach.
Another intervention option to treat
ADHD is behavior modification. It is clear that behavior modification
therapies, for youth in particular, have been tested and shown
beneficial for the treatment of behavioral disorders including ADHD.
However, the majority of youth receiving psychological interventions for
ADHD are probably receiving treatments that have not been shown to be
effective, such as individual therapy and/or play therapy. The
effectiveness of behavioral interventions must be further studied in the
treatment of ADHD, to better understand their potential to normalize the
behavior and functioning of those with the disorder, especially when
combined with pharmacotherapy.
Access to interventions is a critical
public health concern. ADHD affects a person's ability to learn and be
socialized to his/her potential; therefore access to diagnosis and
intervention is a necessity. Common barriers to services include lack of
insurance coverage for mental health problems, exclusion of behavior
disorders, including ADHD, from mental health coverage, and
under-identification or mis-identification. Community practice with
respect to the diagnosis of ADHD fails to uniformly employ accepted
methods for establishing cross-situational symptomatology, measurement
of functional impairment, and diagnosis of comorbid conditions.
Nationally, we must begin to look at a wide variety of intervention
issues surrounding ADHD, including how current interventions impact
individuals and systems over time, as well as problems with access to
appropriate services.
Action to Address Public Health Needs
-
Disseminate educational materials
relating to the diagnosis of and intervention opportunities for ADHD.
Recipients should include but would not be limited to primary care
physicians, physician extenders (NP's and PA's), mental health
professionals, and educators.
-
Promote the necessity of careful
case identification using standardized instruments and the employment
of the most effective interventions in common practice by
disseminating useful information to professionals and the public
related evidence-based interventions for ADHD.
-
Conduct population-based studies of
ADHD intervention practices to examine such variables as age of
initiation of treatment, type(s) of treatment, duration of treatment,
and barriers to receipt of services.
-
Establish a mechanism (possibly a
registry) of treated individuals to monitor the health effects and
potential benefits of long-term treatment for ADHD, particularly among
pre-school age children. Additionally collect other related outcomes
such as school attainment, interface with judicial system, work
performance, and other pertinent variables.
-
Collaborate with other
organizations to educate and promote what is known about ADHD
interventions, appropriate standards of practice, their effectiveness,
and their safety.
-
Establish a resource to the public
for accurate and valid information about ADHD and evidence-based
interventions.
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Footnote
1 Although the DSM-IV (1994) cites a
prevalence rate of 3-5% of school age children, methodological issues in
epidemiological research and the evolving dynamics of the disorder have
led to wide variations of reported prevalence estimates that range from
approximately one percent to nearly 20 percent of school age children.