Attention-Deficit/Hyperactivity Disorder (ADD, ADHD)

DSM-5 diagnostic criteria include 9 symptoms and signs of inattention and 9 of hyperactivity and impulsivity. Diagnosis using these criteria requires ≥ 6 symptoms and signs from one or each group. Also, the symptoms need to

Inattention symptoms:

Hyperactivity and impulsivity symptoms:

Diagnosis of the predominantly inattentive type requires ≥ 6 symptoms and signs of inattention. Diagnosis of the hyperactive/impulsive type requires ≥ 6 symptoms and signs of hyperactivity and impulsivity. Diagnosis of the combined type requires ≥ 6 symptoms and signs each of inattention and hyperactivity/impulsivity.

Differentiating between ADHD and other conditions can be challenging. Overdiagnosis must be avoided, and other conditions must be accurately identified. Many ADHD signs expressed during the preschool years could also indicate communication problems that can occur in other neurodevelopmental disorders (eg, autism spectrum disorders Autism Spectrum Disorders Autism spectrum disorders are neurodevelopmental disorders characterized by impaired social interaction and communication, repetitive and stereotyped patterns of behavior, and uneven intellectual... read more ) or in certain learning disorders Overview of Learning Disorders Learning disorders are conditions that cause a discrepancy between potential and actual levels of academic performance as predicted by the person’s intellectual abilities. Learning disorders... read more , anxiety Overview of Anxiety Disorders in Children and Adolescents Anxiety disorders are characterized by fear, worry, or dread that greatly impairs the ability to function normally and that is disproportionate to the circumstances at hand. Anxiety may result... read more , depression Depressive Disorders in Children and Adolescents Depressive disorders are characterized by sadness or irritability that is severe or persistent enough to interfere with functioning or cause considerable distress. Diagnosis is by clinical criteria... read more , or behavioral disorders Overview of Behavioral Problems in Children Many behaviors exhibited by children or adolescents concern parents or other adults. Behaviors or behavioral patterns become clinically significant if they are frequent or persistent and maladaptive... read more (eg, conduct disorder Conduct Disorder Conduct disorder is a recurrent or persistent pattern of behavior that violates the rights of others or violates major age-appropriate societal norms or rules. Diagnosis is by clinical criteria... read more ).

Clinicians should consider whether the child is distracted by external factors (ie, environmental input) or by internal factors (ie, thoughts, anxieties, worries). However, during later childhood, ADHD signs become more qualitatively distinct; children with the hyperactive/impulsive type or combined type often exhibit continuous movement of the lower extremities, motor impersistence (eg, purposeless movement, fidgeting of hands), impulsive talking, and a seeming lack of awareness of their environment. Children with the predominantly inattentive type may have no physical signs.

Medical assessment is focused on identifying potentially treatable conditions that may contribute to or worsen symptoms and signs. Assessment should include seeking a history of prenatal exposures (eg, drugs, alcohol, tobacco), perinatal complications or infections, central nervous system infections, traumatic brain injury, cardiac disease, sleep-disordered breathing, poor appetite and/or picky eating, and a family history of ADHD.

Developmental assessment is focused on determining the onset and course of symptoms and signs. The assessment includes checking developmental milestones, particularly language milestones, and the use of ADHD-specific rating scales (eg, the Vanderbilt Assessment Scale, the Conners Comprehensive Behavior Rating Scale, the ADHD Rating Scale-V). Versions of these scales are available for both families and school staff, allowing assessment across different situations as required by DSM-5 criteria. Note that scales should not be used alone to make a diagnosis.

Educational assessment is focused on documenting core symptoms and signs; it may involve reviewing educational records and using rating scales or checklists. However, rating scales and checklists alone often cannot distinguish ADHD from other developmental disorders or from behavioral disorders.

Stimulant preparations that include methylphenidate or amphetamine salts are most widely used. Response varies greatly, and dosage depends on the severity of the behavior and the child’s ability to tolerate the drug. Dosing is adjusted in frequency and amount until the optimal balance between response and adverse effects is achieved.

Methylphenidate is usually started at 0.3 mg/kg orally once a day (immediate-release form) and increased in frequency weekly, usually to about 2 to 3 times per day or every 4 hours during waking hours; many clinicians try to use morning and midday dosing. If response is inadequate but the drug is tolerated, dose can be increased. Most children find an optimal balance between benefits and adverse effects at individual doses between 0.3 and 0.6 mg/kg. The dextro isomer of methylphenidate is the active moiety and is available for prescription at one half the dose.

Dextroamphetamine is typically started (often in combination with racemic amphetamine) at 0.15 to 0.2 mg/kg orally once a day, which can then be increased to 2 or 3 times a day or every 4 hours during waking hours. Individual doses in the range of 0.15 to 0.4 mg/kg are usually effective. Dose titration should balance effectiveness against adverse effects; actual doses vary significantly among individuals, but, in general, higher doses increase the likelihood of unacceptable adverse effects. In general, dextroamphetamine doses are about two thirds those of methylphenidate doses.

For methylphenidate or dextroamphetamine, once an optimal dosage is reached, an equivalent dosage of the same drug in a sustained-release form is often substituted to avoid the need for drug administration in school. Long-acting preparations include wax matrix slow-release tablets, biphasic capsules containing the equivalent of 2 doses, and osmotic release pills and transdermal patches that provide up to 12 hours of coverage. Both short-acting and long-acting liquid preparations are now available. Pure dextro preparations (eg, dextromethylphenidate) are often used to minimize adverse effects such as anxiety; doses are typically half those of mixed preparations. Prodrug preparations are also sometimes used because of their smoother release, longer duration of action, fewer adverse effects, and lower abuse potential. Learning is often enhanced by low doses, but improvement in behavior often requires higher doses.

Dosing schedules of stimulant drugs can be adjusted to cover specific days and times (eg, during school hours, while doing homework). Drug holidays may be tried on weekends, on holidays, or during summer vacations. Placebo periods (for 5 to 10 school days to ensure reliability of observations) are recommended to determine whether the drugs are still needed.

Common adverse effects of stimulant drugs include

Depression is a less common adverse effect and may often represent an inability to easily shift focus (overfocusing). This can manifest as a dulled demeanor (sometimes described by families as being zombie-like) rather than actual clinical childhood depression Depressive Disorders in Children and Adolescents Depressive disorders are characterized by sadness or irritability that is severe or persistent enough to interfere with functioning or cause considerable distress. Diagnosis is by clinical criteria... read more . In fact, stimulant drugs are sometimes used as adjunctive treatment for depression. A dulled demeanor can sometimes be addressed by cutting the stimulant drug dose or trying a different drug.

Studies have shown growth in height slows over 2 years of stimulant drug use, and slowing apparently persists into adulthood with ongoing chronic stimulant drug use.

Atomoxetine, a selective norepinephrine reuptake inhibitor, is also used. The drug is effective, but data are mixed regarding its efficacy compared with stimulant drugs. Some children have nausea, sedation, irritability, and temper tantrums; rarely, liver toxicity and suicidal ideation occur. A typical starting dose is 0.5 mg/kg orally once a day, titrated weekly to 1.2 to 1.4 mg/kg once a day. The long half-life allows once-a-day dosing but requires continuous use to be effective. The maximum recommended daily dosage is 100 mg.

Selective norepinephrine reuptake inhibitor antidepressants such as bupropion and venlafaxine, alpha-2 agonists such as clonidine and guanfacine, and other psychoactive drugs are sometimes used in cases of stimulant drug ineffectiveness or unacceptable adverse effects, but they are less effective and are not recommended as first-line drugs. Sometimes these drugs are used in combination with stimulants for synergistic effects; close monitoring for adverse effects is essential.

Adverse drug interactions are a concern with ADHD treatment. Drugs that inhibit the metabolic enzyme CYP2D6, including certain selective serotonin reuptake inhibitors (SSRIs) that are sometimes used in patients with ADHD, can increase the effect of stimulant drugs. Review of potential drug interactions (typically using a computerized program) is an important part of pharmacologic management of ADHD patients.

Counseling, including cognitive-behavioral therapy (eg, goal-setting, self-monitoring, modeling, role-playing), is often effective and helps children understand ADHD and how to cope with it. Structure and routines are essential.

Classroom behavior is often improved by environmental control of noise and visual stimulation, appropriate task length, novelty, coaching, and teacher proximity.

When difficulties persist at home, parents should be encouraged to seek additional professional assistance and training in behavioral management techniques. Adding incentives and token rewards reinforces behavioral management and is often effective. Children with ADHD in whom hyperactivity and poor impulse control predominate are often helped at home when structure, consistent parenting techniques, and well-defined limits are established.

Elimination diets, megavitamin treatments, use of antioxidants or other compounds, and nutritional and biochemical interventions have had the least consistent effects. Biofeedback can be helpful in some cases but is not recommended for routine use because evidence of sustained benefit is lacking.