Upon completion of the chapter, the reader will be able to:
Explain accepted criteria necessary for the diagnosis of attention-deficit/hyperactivity disorder (ADHD).
Recommend a therapeutic plan, including drug selection, initial doses, dosage forms, and monitoring parameters, for a patient with ADHD.
Differentiate among the available pharmacologic agents used for ADHD with respect to pharmacology and pharmaceutical formulation.
Recommend second-line and/or adjunctive agents that can be effective alternatives in the treatment of ADHD when stimulant therapy is less than adequate.
Address potential cost–benefit issues associated with pharmacotherapy of ADHD.
Recommend strategies for minimizing adverse effects of ADHD medications.
Attention-deficit/hyperactivity disorder is characterized by a persistent pattern of inattention and/or hyperactivity-impulsivity. It can have a severe impact on a patient’s ability to function in both academic and social environments. Early diagnosis and appropriate treatment are essential to compensate for areas of deficit.
EPIDEMIOLOGY AND ETIOLOGY
KEY CONCEPT This disorder usually begins by 3 years of age but must occur before 12 years of age to meet current diagnostic criteria. In the United States, ADHD is the most common neurobehavioral disorder that affects children.1,2,3,4 ADHD has been estimated to occur in 4.3% to 9.5% of school-aged children.4,5 ADHD occurs more than twice as often in school-aged boys than girls.5
Although ADHD generally is considered a childhood disorder, symptoms can persist into adolescence and adulthood. The prevalence of adult ADHD is estimated to be 2.5 %; however, 60% of adults with ADHD have symptoms that manifested in childhood.6,7,8 Furthermore, problems associated with ADHD (eg, social, marital, academic, career, anxiety, depression, smoking, and substance abuse problems) increase with the transition of patients into adulthood.
KEY CONCEPT The exact pathologic cause of ADHD has not been identified. ADHD is generally thought of as a disorder of self-regulation or response inhibition. Patients who meet the criteria for ADHD have difficulty maintaining self-control, resisting distractions, and concentrating on ideas.4,9,10 Furthermore, children with ADHD often alternate between inattentiveness to monotonous tasks and overexcitement. Multiple brain studies have failed to elucidate any pathophysiologic basis for ADHD.
KEY CONCEPT Dysfunction of the neurotransmitters norepinephrine and dopamine is thought to be key in the pathology of ADHD. Whereas norepinephrine is responsible for maintaining alertness and attention, dopamine is responsible for regulating learning, motivation, goal setting, and memory. Both of these neurotransmitters predominate in the frontal subcortical system, an area of the brain responsible for maintaining attention and memory. Genetics appears to play a role because a child who has a parent with ADHD has a 50% chance of developing ADHD. An association has been made between the development of ADHD and fetal alcohol syndrome, lead poisoning, maternal smoking, and hypoxia.4,10