Attention-deficit/hyperactivity disorder (ADHD) is one of the most frequent diagnoses among schoolage populations. Recent studies have estimated the prevalence at approximately 7% of children ages 3 to 17 years in the United States (Centers for Disease Control and Prevention, 2005). Boys are twice as likely as girls to be diagnosed with ADHD (Bloom & Cohen, 2007). Data have suggested that children who are of poor or fair health status are 3 times more likely to be diagnosed with ADHD than children with better health (Bloom & Cohen, 2007). ADHD is associated with several comorbid disorders; the most common are oppositional defiant disorder (estimated in 40%-65% of individuals with ADHD) and learning disabilities (approximately 31% of individuals with ADHD; DuPaul & Stoner, 1994).Several poor outcomes have been correlated with childhood diagnoses of ADHD. For instance, 12-year-old-children diagnosed with ADHD were found to have significantly lower reading achievement scores, higher rates of absenteeism, increased occurrence of grade retention, and greater incidence of dropping out of school than those without the diagnosis (Barbaresi, Katusic, Colligan, Weaver, & Jacobsen, 2007). Children with ADHD are more likely to have social difficulties that interfere with friendships, family interactions, leisure activities, and occupational performance than peers without ADHD (Mannuzza, Klein, Bessler, Malloy, & Hynes, 1997;Strine et al., 2006). Furthermore, children with disabilities including ADHD have been found to have a higher prevalence of nonfatal injuries (Schubiner et al., 2000;Xiang, Stallones, Chen, Hostetler, & Kelleher, 2005) as well as higher rates of substance abuse (Levin & Kleber, 1995). Collectively, these statistics suggest that early diagnosis and intervention for children with ADHD is paramount in improving their quality of life.
DIAGNOSIS AND ASSESSMENTThe Diagnostic and Statistical Manual of Mental Disorders (4th ed., text revision; DSM-IV-TR; American Psychiatric Association, 2000) describes ADHD as an ongoing pattern of inattention, hyperactivity, or both that occurs more often or to a greater extent than is developmentally typical. ADHD is divided into three subtypes: predominantly inattentive type, predominantly hyperactive-impulsive type, and combined type. Diagnosis and classification into one of these subtypes is usually made by matching observed behaviors to symptoms listed as diagnostic criteria in the DSM-IV-TR. Because the symptoms of ADHD occur periodically in most people, the symptoms must have been present for at least 6 months and occur at a level that is both disruptive and developmentally inappropriate.