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Attention-deficit hyperactivity disorder is the most common behavioral disorder diagnosed during childhood and adolescence, with 2.8% of all youths 5 to 18 in the United States receiving methylphenidate in 1995. The conventional cardinal symptoms of ADD include age-excessive inattentiveness, usually in association with overactivity and impulsivity. Newer data and recommendations now support that a distinct subgroup of patients have ADD without hyperactivity or impulsivity.
To diagnose ADD, clinicians must judge the duration, frequency, intensity, pervasiveness, and maladaptive nature of these behaviors while excluding a myriad of other possible causes. Furthermore, these behaviors must be differentiated from normal age-related variations, mood disorders.
Teachers or parents frequently comment that untreated children manifest no problems on some "good days" or while watching television or playing video games. They assume that if the behavior can be modulated some of the time, then the child is not hyperactive. Even after the patient has shown dramatic improvement with medication, adults may still complain that some days the child's behavior is worse than at baseline.
Most medication for ADD is prescribed by physicians in general practice, not neurologists or psychiatrists, with more than half of stimulant prescriptions written by pediatricians. More than 80% of these prescriptions are written for school-aged children. Because of the inherent complexity and difficulty.
In the past, pediatricians have generally considered the diagnosis of ADD only in those children who displayed overt overactivity, aggressiveness, or behavioral problems. Another misconception has been that, as children progress into adolescence and adulthood, ADD is outgrown primarily because the "cardinal symptom," overactivity, subsides. Instead, inattentiveness, restlessness.
Disorder
Most children with ADD-H present during preschool and elementary school years with behavioral problems. Usually, parents bring the child to the office complaining of either their child's hyperactivity,
In contrast, patients with ADD-I usually present in middle or high school years, predominantly with academic problems. August and Garfinkel coined ADD-I as the "cognitive deficit" form of ADD.
Comorbid disorders may be observed in as many as two thirds of children referred to a tertiary-care clinic for ADD. Patients with ADD-H are more frequently affected by comorbid conduct disorders (36%-50%) and oppositional defiant disorder (59%). Among a tertiary-care hospitalized referral population with ADD-H and ADD-I, Eiraldi and colleagues observed conduct disorders in 44% and 0% of patients, respectively, and oppositional defiant disorder.
Schachar and colleagues reported a worse prognosis and lower cognitive functioning among pervasively versus situationally hyperactive children. Early age of ADD onset is associated with higher cognitive deficits, poor reading skills, comorbidity at age 11 years, and worse outcome at age 15 years. Clinical course and outcomes are significantly worse in those with ADD-H comorbid with conduct disorders, aggression.
No chemical, serologic, or imaging tests are available to diagnose ADD. In addition, pediatricians have limited observation of the patient's behavior. Thus, to diagnose ADD, pediatricians must rely on the "foundation," the subjective parental, patient, and social history; the "cornerstone," the objective behavioral checklist from the teacher(s); and the "mortar," the physician gestalt regarding the patient and family dynamics.
A single checklist for both age groups-adolescents and children-should be selected and uniformly used within an office. To diagnose ADD, the checklist should be obtained from both the parents/caregivers and teachers. Using both sources improves the accuracy of the diagnosis by providing information regarding behavior from two different vantage points: parents have a long-term (and biased) view of their child in multiple milieus; teachers have a short-term, more objective, and reliable viewpoint and are able to compare the patient with 30 other students (control subjects) in the classroom. The school setting singularly places the most intense demands on concentration. Each assessed environment has its own set of diverse requirements of both attention and social behavior.
The current criteria for diagnosing ADD are listed in DSM-IV. Furthermore, according to DSM-IV in order to diagnose ADD, the clinician must also ascertain the following:
| Medication | Dose | Duration | Titration | Advantages | Disadvantages |
|---|---|---|---|---|---|
| Methylphenidate (Ritalin) 5, 10, 20 mg |
0.3 to 0.6 mg/kg/dose b.i.d. or t.i.d. | 2 to 4 hours | Pills can be cut in half, but difficult | Most popular stimulant; least negative effects on appetite and mood. Not labelled as "speed" or diet pill. | Some differences between brand-name and generic, too short-acting, requires multiple dosing. Worse peaks and troughs. Recent negative press. Not approved for children < 6 years of age. |
| Methylphenidate SR (Ritalin SR) |
0.5 to 0.7 mg/kg/dose q.d. or b.i.d. | 2 to 6 hours Erratic |
None | Lowest rate of AEs among long-acting formulations | Erratic, unreliable pharmacokinetics, occasional differences between brand-name and generic. |
| Dextroamphetamine sustained release capsules (Dexedrine Spansule) 5, 10, 15 mg |
0.15 to 0.3 mg/kg/ dose q.d. or b.i.d. | 5 to 7 hours | Capsules can be split in half (2.5 mg increments). See text. | May be sprinkled for children unable to swallow pills. Less abuse potential than tablets. | Appetite suppression and moodiness somewhat more common than with methylphenidate; avoid vitamin C simultaneously. Administer prebreakfast. Higher abuse potential. |
| Dextroamphetamine tablets (Dexedrine) 5 mg tablets |
0.15 to 0.3 mg/kg/ dose b.i.d. | 3 to 5 hours | Easy to cut in half | Longer duration than short-acting methylphenidate | (Same as spansules). Requires more frequent administration. Common form of "speed" on the street. Higher abuse potential. |
| Mixture of amphetamine salts (Adderall) 5, 10, 20, 30 mg |
0.15 to 0.3 mg/kg/ dose q.d. or b.i.d. | 5 to 7 hours | Easy to cut in half (2.5 mg increments). | Reliable long-acting preparation, easiest of all medications to titrate, approved for 3 years and older. | No recent published clinical trials. Otherwise apparently similar to dextroamphetamine spansules. Higher abuse potential. |
| Pemoline (Cylert) 18.75, 37.5, 75.0 mg tablets and 37.5 mg chewables |
1-2 mg/kg/day qd (once a day) | 12 to 24 hours Longest acting of all |
Easy. Half-doses may be administered. Effects may not be apparent for several weeks. | Longest-acting preparation, usually single daily dose. No abuse potential. Not considered a potential "street" drug. Alternative for adolescents or for patients with frequent homework. | Lower rates of efficacy compared with other stimulants. Requires informed consent before prescribing and frequent serologic monitoring of LFTs. Onset of action may be from 3 days to 3 weeks. |
| Clonidine (Catapres) Transdermal patches [TTS (1, 2, or 3)] |
Start with 0.05 mg or tid or qid oral form. Increase by 0.05 mg tid weekly. Try transdermal patches replaced every 3 to 5 days in stable patients. | Pills 4 to 6 hours Patches 3 to 5 days | Half-doses can be used for pills or patches. Weekly increased dosing usually necessary. | Most helpful in children with aggression, extreme overactivity, or conduct disorders. Use concomitantly with psychostimulants. Preferred therapy for children with concomitant tic disorder. | Significant or severe problems with sedation. Not effective for inattention. Brand-name may be preferred over generic. Not FDA approved for behavioral pharmacotherapy. Discontinue gradually to prevent rebound hypertension. |
| AEs, adverse effects; LFTs, liver function tests; TTS, transdermal therapeutic system. | |||||
Initial therapy in children diagnosed with uncomplicated ADD always consists of one the psychostimulants: methylphenidate, dextroamphetamine, or a combination of dextroamphetamine and levoamphetamine (Adderall). These medications are extremely safe and require no serologic or hematologic monitoring. Patients may respond better to one or the other of these psychostimulants, and patients who do not respond to the initial choice can be treated with either remaining alternative. Interestingly, parent-rating scales favored dextroamphetamine over methylphenidate, probably secondary to the longer half-life of dextroamphetamine so that effects were observed at home and school.