Attention Deficit Hyperactivity Disorder (ADHD)

Attention Deficit Hyperactivity Disorder, occurs in approximately 3 to 5 % of school age children and in many cases, persists into adolescence and adulthood. The disorder has been a source of controversy for many years, since it represents an extreme form of commonly occurring childhood behaviors. ADHD is diagnosed by looking at multiple behavior symptoms. This system is derived from the standard American Psychiatric Manual, (DSM-IV), that is used by mental health professionals to establish criteria for specific mental health disorders in children and adults.

Hundreds of clinical studies have supported the validity of the DSM-IV criteria for this condition, although the diagnosis in a particular child may still be a source of debate. Ongoing scientific studies will attempt to define biological markers that can be used to confirm the diagnosis.

What are the different types of ADHD?

Not all children with ADHD show the same symptoms. Some symptoms, such as academic problems, may not become obvious until the child is older. In others, behaviors may vary for different people ( mom vs dad ), or in different situations ( home vs school ). The child may attend well to a favorite video game but not when doing homework or household chores.

Many distinguish at least three types of ADHD, including:

• Inattentive type: These children are very distractible and have a major problem with focus. This form of ADHD can present at a later age with increasing problems in school. Since these children may not show signs of hyperactivity, the diagnosis may be delayed for years. Some impulsive behavior may be exhibited, especially in test taking or homework completion.

• Hyperactive type: These children may also be inattentive, but have a markedly increased motor activity compared to their age group. For some, the "terrible twos" never end. Some children are described as restless, fidgety, or "on the go", with excessive running and climbing. This type is most prominent in younger children.

• Combined type: This is the most common of ADHD, with the child showing signs of hyperactivity when young, followed by more impulsive and off-task behaviors as the child gets older.

What role does genetics play in ADHD?

ADHD has a strong genetic component. Genetic studies are in progress to find out if specific chromosome studies can be done to pinpoint the cause in an individual child. In many families, however, a pattern can be seen that suggests that other family members either are involved or may have been affected when younger.

Although researchers have attempted to look at ADHD in various cultures around the world, this is difficult due to differences in diagnostic criteria and interpretation of behavior. At this time, no major cultural differences have been found.

Differences based on sex have been reported, with children referred to a psychiatrist showing a boy-to-girl ratio of between 3:1 and 9:1. Others, however, have noted a ratio closer to 2:1 in school age children with the ratio becoming almost 1:1 in adolescents. A recent report noted that women predominate in young adulthood and the inattentive form includes many more girls than the hyperactive type.

Will ADHD go away?

Years ago it was assumed that ADHD would disappear later in childhood. More recent studies show that the signs and symptoms often persist into early adolescence. The number of symptoms, however, seems to decrease with age. When the behaviors persist into adolescence, academic underachievement may occur. Some of these children also have greater social interaction issues compared to their peers, including a higher rate of substance abuse. For those who improve during later childhood, there are fewer problems with social interactions and substance abuse, but many still struggle to maintain academic success.

What other problems occur with ADHD?

Some children have other behavior disorders that can complicate the management of ADHD. At least 20% of children with ADHD may have a learning disability that can make school frustrating. This usually involves a problem with reading (in some cases, a marked dyslexia). This can become a bigger issue in the higher grades. Problems in math may be present and, weak organizational skills may need improvement, especially as homework increases in the higher grades. Psychological consultation and testing are helpful in evaluating these difficulties.

Some children also have significant problems with oppositional behavior and conduct (up to 50% in some studies). Oppositional defiant disorder (ODD) may begin at about age two such that the "terrible twos" do not end by age three. Conduct disorder is another behavioral issue that can result in defiant, non-compliant behavior and poor social interaction. A combination of behavioral therapy and medication may be useful. Anxiety disorders (25%) and mood disorders, including major depression (5-15%), present additional risk factors for normal development.

Is ADHD a neurological disorder?

Research in animals and humans supports the current understanding of ADHD as primarily a disorder of the central nervous system. Neuroscientists in many different fields point to abnormalities within several neurochemical pathways in the brain that produce the clinical symptoms we associate with ADHD.

Localized problems in the prefrontal cortex of the brain and its connections to the basal ganglia, the deeper structures controlling motor behavior, have been implicated in many studies. The prefrontal cortex, as the "executive" area of the brain, coordinates many complicated functions and provides inhibitory control over the motor functions originating in the basal ganglia, with a "feedback loop" returning nerve signal back to the frontal region. One of the major connections involves a chemical pathway utilizing the neurotransmitter, dopamine. Stimulant medication, such as Ritalin, exerts its influence on dopamine type pathways, which may explain some of their clinical effects in children with ADHD. Ongoing research should lead to a biological marker for the disorder which would greatly help in diagnosis.

What testing is available to help diagnose ADHD?

Behavior rating scales have been developed by psychologists to help identify sets of behaviors that, when taken together, support the diagnosis. Common ones are the Conners Rating Scale (CRS) and the Achenbach. Different schools may use other similar scoring sheets. These tests can be done over time to assess the student's progress and success/failure of medical treatment.

Testing is available from child psychologists. These are tests of attention span, one of which is the TOVA (test of variables of attention), a computerized game the student takes. Scores in areas, such as inattention and impulsivity, are compared to his/her age group.

In some schools, direct observation of the child in the classroom, particularly of "off-task" behavior, can support the diagnosis of ADHD.

Medications for treatment of ADHD

The goal of medication in children with ADHD is to improve the symptoms of ADHD. Studies have shown that 70-80% of children with ADHD have a positive response to medication, especially the stimulant medications, such as Ritalin. The results are improved attention span, decreased impulsivity and more on-task behavior, in a structured setting, such as school. Many show better compliance with rules and become less frustrated. Some develop an improved relationship with peers, parents and teachers.

Medications for ADHD act on chemical neurotransmitter systems in the brain. Brain cells are electrical. They communicate to each other through a gap between neurons by the release of chemicals called neurotransmitters. Stimulant medications act on these systems and possibly restore a "balance" biochemically with resultant improvement in the ADHD symptoms. Since 1937, stimulant medications have been used most frequently. Other nonstimulant drugs can also be helpful.

The dose of stimulant medication must be chosen for each child based on age and size, starting with the lowest possible dose that might be effective. Based on the observations of parents, teachers and the doctor (and/or use of rating scales and the TOVA test), the dose may be increased or given more often, if it wears off too soon.

The dose and number of administrations will depend upon the preparation of drug chosen. For example, the short acting Ritalin (methylphenidate) may only last 3-4 hours so the sustained release (SR) form may get the child through the school day. After school, however, the (SR) preparation may last close to bedtime and cause insomnia, so the last dose may be the shorter acting type. Adjustments can take many weeks before a maximally effective dose is found. A change in medication may be necessary when children respond to one stimulant but not another. The dose may need to be increased over time or in those who improve (usually by the early teens), the medication can be stopped.

Fortunately, side effects are typically infrequent, mild and short-lived. In some, however, lowering the dose may not improve the side effects. With stimulants a "rebound" effect (increased moodiness and activity level) may result as the drug wears off; this can usually be managed by altering the dose or timing of the medication. Most will experience an initial decrease in appetite (especially at lunch), but this typically improves over time. Long-term growth studies in medicated children with ADHD have not shown problems. If given too close to bedtime, these drugs may cause some insomnia and the timing of the last dose may need to be adjusted.

In a few children, involuntary motor or verbal tics may be "unmasked" by the medication. Although these drugs do not "cause" tics, higher doses may bring out abnormal eye blinking, throat clearing or facial grimaces. Lowering or stopping the drug is usually helpful, although tics can vary greatly on their own. About 1% of children with Tourette's Syndrome also have ADHD, but many can still take these medications without increasing their tic disorder. A rare, but serious, side effect has been reported only with pemoline involving abnormal liver function. Frequent liver function testing will be needed.

Other medications such as antidepressants can be used. Clonidine may help hyperactivity and temper problems in some younger children. It may also decrease tics; however, it can cause sedation and must be slowly increased. Antidepressants work in the absence of depression, but side effects such as fatigue, appetite loss and insomnia may occur. The antidepressant group also takes much longer (several weeks) to produce a clinical response.

Will stimulant use increase the risk of substance abuse later?

No. There is no scientific evidence from long-term studies suggesting that chronic use of these medications directly leads to substance abuse in later life. Although the ADHD population as a whole has a higher risk of substance abuse, this is not secondary to medication use.

How long will it take to judge if the drug works?

Stimulant medication begins to work in 30-60 minutes, with positive effects peaking in several hours and then wearing off over 4 to 9 hours. For some, the "duration of action" is much shorter. It may take several weeks to arrive at the most effective dose and timing, depending on the drug. Antidepressants are much slower in onset of action and may need several months to maximize the dosage.

Can medication be given only in school?

For some, treatment only during school days is fine, with an occasional dose for a big weekend homework project. In the higher grades, it may be necessary to give an after-school or weekend dose to improve attention span during intense homework assignments. Others may use the drug for special events that require a long period of attention, such as weddings or religious events. Rarely, it could be considered for sporting events.

Will my child outgrow the need for medication?

Studies suggest that perhaps 50% of children will have symptoms of ADHD into adulthood; however, many improve over time and learn to compensate, with some adolescents coming off stimulant drugs by age 15 years.

Will my child need to take more than one medication?

For those with co-existing conditions, such as depression or aggressive conduct problems, other medications may be necessary. Stimulant drugs may not help mood problems commonly seen in teenagers. The child may be on a combination of medications for a time. When more than one drug is prescribed, drug interactions need to be considered.

Does diet or herbal therapy work?

Although many diets, such as the low sugar and Feingold, have come and gone none have proven to be very effective. Large doses of multivitamins over time have also not shown consistent, positive responses in most children. Herbal therapies have been used for many years, but at this time no scientific studies to support their use.

Can behavioral therapy be helpful?

Yes. Most will benefit from a behavior modification approach at home and school, and some children may need more intense help from a child psychologist. Learning problems need to be addressed and good behaviors rewarded. Parent and teachers must be firm, but flexible. Many experts feel that behavior therapy works better when combined with medication.

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