Free «Attention Deficit/Hyperactivity Disorder (ADHD)» Essay Paper

Introduction

A great success in studying of one of the most actual problems of neuropediatric – Attention Deficit/Hyperactivity Disorder (ADHD) – has been achieved recently. The children suffering from ADHD have an average or high IQ level, but study bad at school. Except the difficulties in education, ADHD is revealed in a motive hyperactivity, defects of attention concentration, impulsiveness of behavior and problems in the relationship with people around. ADHD is observed both among children and adults. Its genetic nature has been proved in recent researches. However, many scientists doubt whether ADHD can be recognized as a mental disorder or not. Some scientists deny the existence of such disorder as a psychological phenomenon (DuPaul & Stoner, 2003).

Current scientific problem attracts the interests of various experts - pediatricians, teachers, neuropsychologists, speech pathologists and neurologists. The fact that ADHD does not belong to the disability diseases does not mean that there is no need for its therapy. Thus, Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurologic and behavioral disorder of development, beginning at children’s age. It is revealed by such symptoms as difficulties of attention concentration, hyperactivity and badly operated impulsiveness. From the neurologic point of view, ADHD is considered to be a stable and chronic disorder without any known way of treatment. It is considered that children “overgrow” the syndrome or adapt to it in adulthood (American Academy of Child and Adolescent Psychiatry, 2007). The given research paper will discuss the neurological basis of ADHD, caused by the specific deficiency in norepinephrine and dopamine, as well as epidemiology, etiology and symptomatology of the disease. Recent drugs, such as Adderall, increase the production and block the reuptake of these neurotransmitters. However, long-term effects of such stimulants are correlated with neurodegenerative disorders due to the stress it has on the brain.

A Brief Review of Neuropathology

ADHD is the name for the etiological heterogeneous group of behavioral disorders at children older 5. Such changes of behavior are followed by the attention deficit and hyperactivity, which potentially result in a poor learning progress, antisocial behavior and decrease of a life quality. At present, the neurobiological nature of ADHD is established, but its pathogenesis is partially studied (Milich, Ballentine, & Lynam, 2001).

ADHD is the dysfunction of the central nervous system (mainly reticular formation of a brain), revealed in the difficulties of concentration and maintenance of attention, violations of training and memory and also difficulties of exogenous and endogenous information and incentives processing. The term “ADHD” was firstly introduced in the early 1980s from the broader concept “minimal brain injury”. The history of the minimum brain dysfunction studying is connected with the researches of E. Kahn (1934), though separate researches were conducted much earlier. Observing the children of school age with such behavioral disorders as a motor disinhibition, hyperprosexia, impulsiveness of behavior, the researcher suggested that the injury of a brain of an unknown etiology is the reason of the changes, and offered the term “minimal brain injury”. Later, his concept also included educational disorders (difficulties and specific disorders in training to the skills of writing, reading and counting; violations of perception and speech). Subsequently, the static model of “minimal brain injury” resulted in appearance of more dynamic and more flexible model of “minimal brain dysfunction” (Skounti, Philalithis, & Galanakis, 2007).

In 1980, The American Psychological Association (APA) developed the working classification - DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition), according to which the cases described earlier as the “minimal brain dysfunction” were called “Attention-Deficit/Hyperactivity Disorder”. The most frequent and significant clinical symptoms of the minimum brain dysfunction included attention deficit and hyperactivity. In the latest classification of DSM-IV such syndromes are integrated under the name “ADHD” (Biederman & Faraone, 2005).

Epidemiology

As well as in a case with indigo children, 95% of children and teenagers with an inexpressibly deep inner world and non-standard view of reality fall under the name “ADHD”. The genetic cause of ADHD is peculiar from 40% to 75% of the disorder cases. A biochemical substratum in the pathogenesis of ADHD includes the violations of a catecholamine exchange. The influence of the environment and other factors, such as prematurity, a low body weight at birth, smoking of a mother during pregnancy, etc., is taken into consideration but is less significant (Skounti, Philalithis, & Galanakis, 2007).

The frequency of ADHD varies from 2.2 to 18% among the children of school age. Such distinctions are caused by the non-compliance with the accurate criteria of the diagnosis. According to data of the APA, about 5% of children of school age suffer from ADHD. There is at least one child with such disease practically in each school class (Rojas & Chan, 2005).

From an estimated 150,000 to 200,000 children in the United States treated with stimulants at the end of the 1960s, as of 2005, current estimates stand at 4.4 million children diagnosed with ADHD, of whom 56 percent or 2.5 million receive medication. Prescription sales data have been available for psychostimulant drugs since 1971, when they were recategorized as Schedule II controlled substances with mandatory reporting requirements (Effective Health Care Program, 2011).

According to the research conducted by Banerjee, Middleton, Faraone (2007), ADHD is present at 3-5% of people, including both children and adults. Boys suffer from ADHD twice more often than girls. The relative prevalence among boys and girls fluctuates from 3:1 to 9:1, depending on the criteria of the diagnosis, methods of research and research groups. The prevalence of ADHD depends on such factors (Banerjee, Middleton, & Faraone, 2007).

Symptomatology

The existence of training and social functions disorders is a necessary criterion for the establishment of ADHD diagnosis. Moreover, the diagnosis is put when there are difficulties in education. The Effective HealthCare Program (2011) states that “ADHD symptoms exist on a continuum in the general population and are considered a “disorder” to a greater or lesser degree, depending on the source of identification (e.g., parent or teacher), extent of functional impairment, diagnostic criteria, and the threshold chosen for defining a “case” (The Effective HealthCare Program, 2011).

The diagnosis of ADHD can be established in the presence of at least 6 of the symptoms described below. A child has attention deficiency, if he/she:

• Does not pay attention to details and makes mistakes in work;
• Is not attentive in a work or game;
• Does not listen what he is spoken of;
• Is not able to follow instructions;  
• Cannot organize games or activities;
• Has difficulties in the performance of the tasks demanding a long concentration of attention;
• Often loses things;
• Easily distracts his/her attention;
• Is forgetful (Abikoff et al., 2004).

The diagnostics of hyperactivity requires the existence of at least 5 of the listed below symptoms. A child is hyperactive, if he/she:

• Makes the fussy movements by hands and legs;
• Often jumps at his/her seat;
• Is hyperactive in the situations when hyper mobility is unacceptable;
• Cannot play “silent” games;
• Is always in movement;
• Speaks much.

A child is impulsive (is not capable to stop and think before speaking or making action), if he/she:

• Answers a question, without having listened to it;
• Cannot wait for his/her turn;
• Interferes into the conversations and games of the others.

Table 1.

The Diagnostic Features of ADHD.

The diagnosing of ADHD requires the existence of 6 or more symptoms like carelessness, hyperactivity and impulsiveness, which are manifested within at least 6 months and are expressed in the insufficient adaptation and discrepancy to normal age characteristics. The clinical picture of ADHD is defined not only by the excess physical activity and impulsiveness of behavior, but also by disorders of cognitive functions (attention and memory) and motive awkwardness caused by static-motor insufficiency. At the neurologic check-up of a child with ADHD or without it a focal neurologic symptomatology is, as a rule, absent. Insufficiency of a thin motility, disorders of the reciprocal coordination of movements and a moderate ataxia can be observed. Moreover, speed disorders can also take place (Skounti, Philalithis, & Galanakis, 2007).

There are three variants of the ADHD progress, depending on the prevailing symptoms:

1. Hyperactivity disorder without attention deficiency;
2. Attention deficiency without hyperactivity;
3. Combination of attention deficiency and hyperactivity (the most widely-spread).

Besides, there are simple and complicated disease forms. The first one is characterized only by carelessness and hyperactivity, while the second one - by headaches, tics, stutter and sleep disorders. Moreover, ADHD can be both primary and secondary - a consequence of the other diseases or patrimonial injuries and infectious defeats of the central nervous system, for example, after the flu (Biederman & Faraone, 2005).

Etiology

The exact cause of the emergence of ADHD is unknown, but there are some theories. The most widely-spread etiological hypotheses include: 1) genetic; 2) neurochemical; 3) neurobiological; 4) connected with executive functions; 5) ecological. Most of researchers assume the genetic nature of the disorder as there are close relatives who had similar disorder at school age in families of children with ADHD. The fact proving the genetic predisposition of ADHD is that parents of children, suffering from such disorder, often had the same symptoms in the childhood (Wallis, Russell, & Muenke, 2008).

The scientists of the USA, the Netherlands, Colombia and Germany made the assumption that 80% of ADHD cases emergence depends on genetic factors. Among more than 30 genes-candidates, 3 are composed by the dopamine carrier gene and 2 genes of dopamine receptors. The children with the most expressed hyperactivity have the carriers of a mutant gene. However, genetic prerequisites to the development of ADHD are shown in the interaction with the environment, which can strengthen or weaken such prerequisites (Wallis, Russell, & Muenke, 2008).

Except genetic factors, there are also family, pre-and perinatal risk factors of the ADHD development. The family factors include a low social status, existence of a criminal environment, extreme disagreements between parents, etc. The neuropsychiatric disorders, alcoholism and deviations in a sexual behavior are considered to be especially significant. The pre-and perinatal risk factors of the ADHD development include asphyxia of newborns, the use of alcohol by a pregnant mother, some medicines, smoking, immunological incompatibility (by a Rhesus factor), miscarriages threats, chronic diseases of a mother, premature, transient or long birth, stimulation of patrimonial activity, poisoning with anesthesia, the Cesarean section, patrimonial complications (a wrong fetal presentation, a loop of cord). There is a correlation between the behavioral disorder of children at school and a low body weight at the child’s birth (Schonwald & Lechner, 2006).

Children, born with a very low body weight (less than 1500) experience the behavioral disorders at early school age. They are especially caused by hyperactivity. Almost all diseases of babies belong to the postnatal factors. Asthma, pneumonia, heart failure, diabetes, diseases of kidneys can act as factors breaking a normal work of a brain. A number of scientific works discuss the question of a food role in a syndrome origin. Food additives, containing salicylates can lead to a child’s hyperactivity. There was an improvement in a state and decrease in hyperactivity when food additives were excluded from a diet at 30-35% of children. The diet of such children consisted of meat, milk and meals prepared only in house conditions. Although genetic factors are the main causes of ADHD, it is quite probable that the genetic factors interact with the environmental factors, in addition to the difficult interaction between the level of dopamine and norepinephrine (Tab. 1) (Biederman & Faraone, 2005).

Table 2

ADHD Etiological Factors (source: Mosholder, 2006).

According to the research conducted by the WHO (2004), the cornerstone of the ADHD pathogenesis includes the disorders of the activating system of the reticular formation, which promotes the coordination of learning and memory, processing of the arriving information and spontaneous maintenance of attention. The disorders of the activating function of a reticular formation are, most likely, connected with the insufficiency of norepinephrine in it. The impossibility of the adequate information processing leads to the different superfluous visual, sound and emotional incentives for a child, causing an interest, irritation and aggression. Disorders in the functioning of a reticular formation predetermine the secondary disorders of a neuro-mediators exchange of a brain. The theory about the communication of hyperactivity with the disorders of a dopamine exchange has numerous confirmations, in particular, success of ADHD therapy by the dopamine preparations. The disorders leading to hyperactivity are connected with the mutations in genes, which regulate the functions of dopamine receptors. The separate biochemical researches of children with ADHD testify that there is a disorder of the exchange not only of dopamine in a brain but also other of neuro-mediators - serotonin and norepinephrine (WHO, 2004).

Besides, a reticular formation in the pathogenesis of ADHD dysfunction of the frontal lobes (pre-frontal bark), sub crustal kernels and the carrying-out ways, connecting them. One of the confirmations of such assumption includes the similarity of neuropsychological disorder of attention in children with ADHD and in adults at the damage of frontal lobes of a brain. At a spectral tomography of a brain, 65% of children with ADHD showed decreased blood-groove in a prefrontal cerebral cortex at intellectual loadings (Richardson & Puri, 2000).

The first manifestations of ADHD can be sometimes observed in babies during the first year of life. Children with such disorders are excessively sensitive to different irritants (for example, to the artificial light, sounds, different manipulations of a mother, connected with a baby care), are loud crying and experience sleep disorders (hardly fall asleep, sleep a little, often wake up), can lag behind a little in the motor development (start turning over, creeping) and also in speech - they are inert, passive, not emotional. During the first years of life, the main concern of parents regarding their children causes an excess number of a child’s movements, their randomness (motor anxiety). At supervision of such children doctors notice a small delay in their speech development: children start speaking later. There is also a motor awkwardness of such children and they learn difficult movements, such as jumps later (Schonwald & Lechner, 2006).

The age of 3 is special for children. On the one hand, attention and memory actively develop at this period. On the other hand, the first three years’ crisis is observed. The main characteristic features of such period include negativism and obstinacy. A child actively defends the borders of influence on himself as a personality. All such unexpected manifestations are explained by the inability of the central nervous system of the hyperactive child to cope with the new requirements imposed to him against increase in physical and mental activities (Biederman & Faraone, 2005).

The deterioration of the disease course occurs at the beginning of a systematic education (at the age of 5-6). Besides, this age is critical for the maturation of brain structures. Therefore, excess loadings can cause over-fatigue. The emotional development of children suffering from ADHD is late; it is shown by the unbalance and irascibility underestimated by self-assessment. Such signs are often combined with tics, headaches and fears. All such manifestations cause a low progress of children with ADHD at school, despite their rather high intelligence. Such children hardly adapt in class. Owing to the impatience and easy excitability, they often enter the conflicts with the contemporaries and adults that aggravates the available problems with education. A child with ADHD cannot predict the consequences of behavior and does not recognize the authorities. It can lead to the antisocial behavior. Especially often asocial behavior is observed in such children at the teenage period, when the impulsiveness is combined with aggression (Barkley, 2006).