The National Institute of Health, Research Paper Example

Abstract

The National Institute of Health defines attention deficit hyperactivity disorder (ADHD) as an illness that prevents an individual’s ability to remain focused, behave in a socially appropriate manner, and contributes to hyperactivity. Although ADHD appears to cover a broad spectrum of common behaviors, the three ADHD subtypes, including predominantly hyperactive-impulsive, predominantly inattentive, and combined hyperactive-impulsive and inattentive, allow clinicians to make specific diagnoses concerning the patient’s unique symptoms. Of these three subtypes, predominantly hyperactive-impulsive ADHD is common. It is therefore necessary to evaluate this diagnostic subcategory in terms of known or hypothesized etiological factors, relevant psychosocial considerations, ethical considerations, evidence based treatment approaches, considerations related to diverse populations, and discussion of implications for social work practice in order to gain a greater understanding of this illness and its social implications.

Introduction

Attention deficit hyperactivity disorder (ADHD) is a common psychological disorder that is characterized by an individual’s inability to behave in a manner that is appropriate for his or her age. Typically, symptoms begin at ages six to twelve are identified on the basis of a child’s interactions with their learning environment. Despite ADHD’s classification as a psychiatric disorder, many critics of this diagnosis believe that many of the behaviors exhibited by ADHD patients are typical of young children, and that these behaviors may disappear as the child ages and positive behavior is reinforced. However, it is important to note that ADHD is typically diagnosed and treated only in cases in which a child’s behavior is disrupting the learning of others. In this case, the afflicted child will be referred to therapy or medicated depending on the severity of symptoms.

Although ADHD is typically considered a childhood disorder, many adults suffer from these behavioral symptoms as well. As a consequence, it is essential to gain a greater understanding of the biological aspects of this disease and how it may differ for individuals in different age groups. Furthermore, there is a certain stigma that is associated with psychological disorders and patients who are diagnosed with ADHD have a greater potential to be discriminated against in both the workplace and in healthcare due to this health status. Therefore, it is essential to define whether ADHD should be considered a psychological disorder or merely exhibition of behaviors that can be modified without intense therapy. An additional consideration of this illness is that many individuals have displayed symptoms of ADHD throughout their lives. It is therefore necessary to determine at which point an individual should be considered as having ADHD compared to simply exhibiting improper behavior.

While ADHD is broadly classified as a behavioral disorder, there are several disease subcategories. These include predominantly hyperactive-impulsive, predominantly inattentive, and combined hyperactive-impulsive and inattentive ADHD. For an individual’s ADHD to be considered as a part of the predominantly hyperactive-impulsive ADHD spectrum, he or she must have six or more symptoms in the hyperactivity-impulsivity categories and fewer than six symptoms in the inattention category. Individuals with predominantly inattentive ADHD have six or more symptoms in the inattention category and six or less in the hyperactivity-impulsivity category. Individuals with combined hyperactive-impulsive and inattentive ADHD exhibit six or more symptoms in both the hyperactivity-impulsivity and inattentive categories.

Most children have combined hyperactive-impulsive and inattentive ADHD. However it is difficult to conduct experimental studies on these individuals because it is difficult to discern whether these behaviors root from similar or different problems. Therefore, this analysis will focus on individuals with predominantly inattentive ADHD because this ADHD category is readily observable in school-age children and commonly reported as problematic in working adults. This analysis will focus on behavioral symptoms as they relate to school-age children and its implications regarding students from diverse demographic backgrounds. In addition, it will explore the etiology of the disorder and comment upon common treatment.

Literature Review

A major concern in classrooms around the country is that the current version of the Diagnostic and Statistical Manual of Mental Disorders does not adequately describe many of the psychological disorders that are commonly seen in school-age students. If this concern were a reality, then many children who are performing poorly in school could potentially be misdiagnosed as having or not having ADHD. This has been a concern for many years, and in 1997, a group of researchers attempted to identify whether the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders adequately described the behaviors of ADHD diagnosed school children from all three disease subtypes in a study entitled “Behavioral Characteristics of DSM-IV ADHD Subtypes in a School-Based Population” (Gaub et al., 1997). To do so, subjects were compared to controls on teacher ratings of behavioral, academic, and social functioning. It was found that the DSM-IV ADHD subtypes were valid and that all ADHD groups demonstrated impairment relative to controls, but show different patterns of behavioral characteristics. While this study examined an older version of the DSM, the definition of the ADHD subtypes have not changed significantly with the publication of the fifth edition. Therefore, the results found in this 1997 study are relevant to children with ADHD today. We can therefore trust the definition of the requirements for ADHD that the DSM provides in all three categories of the disorder.

Many researchers are critical of the belief that ADHD is a psychological disorder that has biological causes in additional to environmental triggers. A recent article entitled “Joint Analysis of the DRD5 Marker Concludes Association with Attention-Deficit/Hyperactivity Disorder Confined to the Predominantly Inattentive and Combined Subtypes” identifies specific genetic causes of ADHD in several disease subtypes (Lowe et al., 2004). This study identified that the common 148-bp allele of a microsatellite marker located 18.5 kb from the DRD5 gene is associated with ADHD-related behaviors in patient samples. This study demonstrates that there may be several other genetic markers involved in the development of disease that have not yet been identified. While these markers are not known, this study remains important due to the connection it has drawn between genetics and the manifestation of psychological symptoms. Therefore, there is strong evidence that there is a biological cause of ADHD symptoms in addition to environmental, indicating that the use of medication in treatment of the disorder has a basis for efficacy.

While it is useful to understand that ADHD has a genetic cause, it is essential to determine whether the three subtypes of the disease are comparable and have a common etiology. An article entitled “ADHD Combined Type and ADHD Predominantly Inattentive Type Are Distinct and Unrelated Disorders” argues that each disease subtype should be considered independently during diagnosis and treatment (Milich et al., 2006). It was found that both ADHD combined type and ADHD predominantly inattentive type are discernable on the basis of essential and associated features, demographics, measures of cognitive and neuropsychological functioning, family history, treatment response, and prognosis. While the ADHD predominantly hyperactive-impulsive type was not examined in this study, it is reasonable to believe that these characteristics would differ for this disease subtype as well. Further studies are needed to confirm this belief, but doing so would lead to a greater understanding of ADHD and possible reclassification of the three disease subtypes into their own disease categories. In addition, this information indicates that studies of ADHD should consider each subtype separately in most cases in order to prevent drawing inadequate conclusions or finding results that are not statistically significant because the hypothesis is inadequate to explain the phenomenon.

An article entitled “Combined type versus ADHD predominantly hyperactive-impulsive type: is there a difference in functional impairment?” attempts to identify the hyperactive-impulsive symptoms in patients with combined type ADHD and predominantly hyperactive-impulsive ADHD to determine whether there are overlapping disease symptoms (Riley et al., 2008). These differences were identified on the basis of functional impairment in four domains: externalizing (oppositional and disruptive) behaviors, internalizing (anxious) behaviors, social skills, and pre-academic functioning. It was found that there were no behavioral differences between participants with different ADHD subtypes, leading the researchers to conclude that the ADHD predominantly hyperactive-impulsive subtype may represent an earlier form of combined type ADHD. Therefore, it is not important to only consider each ADHD subtype as potentially being a different disorder, but also to explore the possibility that ADHD subtypes may evolve into the others. As a consequence, it may be useful to conduct a large-scale longitudinal study that follows young children before the noticeable development of ADHD throughout the first two decades of their lives to determine whether any significant changes in disease symptoms are observed.

Despite the commonality of ADHD, there has been few attempts to identify disease prevalence in populations outside of the school setting. An article entitled “Prevalence of attention deficit–/hyperactivity disorder (ADHD) and comorbid disorders in young male prison inmates” explores disease prevalence in young male prison inmates (Rosler et al., 2004). It was found that the overall prevalence of ADHD according to DSM–IV was 45%. As stated above, we can assume that these results would be similar if the researchers had assessed prevalence using DSM-V. It is interesting that approximately half of the young male inmates exhibited ADHD symptoms because it marks the disease as a potential risk factor for committing crime. Therefore, it is essential to determine ways that extreme cases of the disease can be detected in young individuals so early interventions can be applied to prevent this kind of behavior.While the DSM clearly indicates the definition of ADHD, a major problem associated with the disorder is an individual’s tendency to diagnose his or herself without a complete understanding of the disease symptoms or the associated severity needed for diagnosis. An article entitled “Self-Report of ADHD Symptoms in University Students: Cross-Gender and Cross-National Prevalence” identifies the individuals who are most likely to engage in this practice (DuPaul et al., 2001). The study found that self-diagnosis did not vary significantly on the basis of gender, although Italian students reported significantly more inattention and hyperactivity-impulsivity symptoms than students from the United States. Furthermore, students from New Zealand reported more inattention symptoms than students from the United States. The prevalence of self-reported ADHD symptoms beyond DSM-IV thresholds for diagnosis ranged from 0% (Italian women) to 8.1% (New Zealand men). Fortunately, it appears that only a small subset of the population attempts to diagnose their own ADHD symptoms. However, there is a clear cultural impact on this phenomenon. In addition, this study does not identify whether these individuals were correct in their diagnosis. It would be useful to examine this question further.

An article entitled “Instability of the DSM-IV Subtypes of ADHD From Preschool Through Elementary School” calls for the need to examine whether the DSM standards apply to children throughout various stages of development (Lahey et al., 2005). As discussed above, the DSM IV and V requirements are fairly consistent and adequately reflect elementary aged children. However, these studies have failed to account for the changes in behavior that occur in children as they age. This study found that the number of children who met criteria for ADHD declined over time, which may be due to failure to report age appropriate symptoms for this individuals, rather than disappearance of symptoms. Therefore, there is a need to define different disease symptoms in individuals of different age groups for all three ADHD subtypes. This will help establish whether each subtype is a different illness and to find a relationship between all three.

Although there are many studies that support the concept that all three ADHD subtypes are distinct, there are some articles that support their similarities. “Genetic Support for the Dual Nature of Attention Deficit Hyperactivity Disorder: Substantial Genetic Overlap Between the Inattentive and Hyperactive–impulsive Components” claims that the genetic nature of two of the ADHD subtypes make them comparable (McLoughlin et al., 2007). It was found that both disease subtypes were highly heritable; predominantly hyperactive–impulsive ADHD was found to be 88% caused by heritability and predominantly inattentive ADHD was found to be 79% caused by heritability. Bivariate genetic modelling indicated substantial genetic overlap between the two components; however, there were significant independent genetic effects.  As a consequence, it is essential to further examine the connection between the three ADHD subtypes. It is possible that a similar genetic basis could result in different phenotype, and it is necessary to define what the behavioral and genetic similarities and differences between the three subtypes are. It is possible that more genes that regulate these behaviors will be identified in the future and that this type of research will contribute to a greater understanding of the disease.

Discussion

A majority of the articles reviewed identified that there is a link between all three ADHD subtypes, but there is much disagreement over what specific qualities this entails. In addition, studies that determine the accuracy of the DSM-IV and DSM-V definitions of ADHD find that definitions are accurate, but only among certain age groups. Therefore, there is a clear need to redefine the definition of ADHD according to stages of childhood development in addition to the specific behavioral subtype observed. Until we can be certain that all three disease subtypes are biologically and psychologically linked, it may be useful to treat each disorder as a separate disease.

This literature review identified many gaps in research that prohibit researchers and clinicians from truly understanding ADHD. While the disease appears to primarily occur in school-age children, many adults have reported disease symptoms. However, the major difference between these two age groups is that in school-age children, the disease symptoms are typically identified by a teacher, who will then refer them to a psychologist for confirmation of diagnosis. Adults who believe they demonstrate ADHD symptoms are more likely to diagnose themselves and act accordingly without having this diagnosis confirmed by a professional. It is therefore difficult to discern whether ADHD is a childhood disease or whether it has similar prevalence in adulthood. This gap of information also contributes to an inability to determine whether individuals who have been formally diagnosed with ADHD exhibit variations of disease symptoms as they age. This information would allow clinicians to correctly diagnose a higher number of individuals.

To resolve these current gaps in research, there is a clear need to conduct a longitudinal study on individuals who are at risk for developing ADHD in order to track the development of symptoms throughout the patients’ lifetimes. During this process, all three ADHD disease subtypes should be considered separately, and this information could be used to track progression of symptoms throughout childhood development and maturity, which will also help identify connections or the lack thereof between the physical symptoms manifested by these patients. In order to gain genetic information regarding the connection between the disorder and its symptoms, it may also be useful to conduct genetic screens. While this type of experiment may not answer all of the questions that are necessary in order to gain a greater understanding of what ADHD truly is, it will be an excellent start that would serve as a guide for further research and clinical practices.

Furthermore, it is essential to gain a greater understanding of the epidemiology of the disease. The primary disease population studied in a majority of cases is school-age children, although few studies tend to examine adult populations. However, since ADHD impact patients more broadly than in learning situations, it would be useful to identify its prevalence in the workplace and among people with certain types of jobs. In both adults and children, it may be possible that certain environmental stressors trigger the expression of disease causing genes. It would therefore be useful to identify what these triggers are because this may be a useful way therapists can instruct individuals to avoid disease development or to lessen associated symptoms.

In conclusion, even though ADHD is a common disorder, there is a great degree of disagreement in the field regarding the etiology and relationship between patient demographics and prevalence. However, it is important to find ways to understand and therefore treat the disorder in a manner that will allow children to behave more appropriately in school situations that will contribute to their ability to learn effectively. Furthermore, understanding the cause of ADHD in children will allow the proper understanding of disease symptoms in adults. There is a clear need to define how disease symptoms differ among members of different demographics and disease subtypes, and a greater understanding of what ADHD is as a whole will help further understanding of both biological and psychological aspects of the disease which will help the many individuals who have been or will be diagnosed with this disorder.

References

DuPaul et al. (2001). Self-Report of ADHD Symptoms in University Students: Cross-Gender and Cross-National Prevalence. J Learn Disabil, 34(4): 370-379.

Gaub M, Carlson CL. (1997). Behavioral Characteristics of DSM-IV ADHD Subtypes in a School-Based Population. Journal of Abnormal Child Psychology, 25(2): 103-111.

Lahey et al. (2005). Instability of the DSM-IV Subtypes of ADHD From Preschool Through Elementary School. Arch Gen Psychiatry, 62(8): 896-902.

Lowe et al. (2004). Joint Analysis of the DRD5 Marker Concludes Association with Attention- Deficit/Hyperactivity Disorder Confined to the Predominantly Inattentive and Combined Subtypes. AJHG, 74(2): 348-356.

McLoughlin et al. (2007). Genetic Support for the Dual Nature of Attention Deficit Hyperactivity Disorder: Substantial Genetic Overlap Between the Inattentive and Hyperactive–impulsive Components. Journal of Abnormal Child Psychology, 35(6): 999-1008.

Milich R, Balentine AC, Lynam DR. (2006). ADHD Combined Type and ADHD Predominantly Inattentive Type Are Distinct and Unrelated Disorders. Clinical Psychology: Science and Practice, 8(4): 463-488.

Riley et al. (2008). Combined Type Versus ADHD Predominantly Hyperactive-Impulsive Type: Is There a Difference in Functional Impairment? Journal of Developmental & Behavioral Pediatrics, 29(4): 270-275.

Rosler et al. (2004). Prevalence of attention deficit–/hyperactivity disorder (ADHD) and comorbid disorders in young male prison inmates. European Archives of Psychiatry and Clinical Neuroscience, 254(6): 365-371.

NIH. (n.d.). Attention Deficit Hyperactivity Disorder (ADHD). Retrieved from http://www.nimh.nih.gov/health/topics/attention-deficit-hyperactivity-disorder-adhd/index.shtml