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This report is based on medical evidence presented at sanctioned medical congress, from peer reviewed literature or opinion provided by a qualified healthcare practitioner. The consumption of the information contained within this report is intended for qualified Canadian healthcare practitioners only.

Canadian Psychiatric Association 2006 Annual Conference

Toronto, Ontario / November 9-12, 2006

Attention deficit/hyperactivity disorder (ADHD) is not just a North American phenomenon but is seen virtually everywhere in the world, stated Dr. Lily Hechtman, Professor of Psychiatry and Pediatrics, McGill University, Montreal, Quebec. The Netherlands and Ireland report the lowest rates (approximately 3%), whereas Ukraine and India report rates that, at 20 and 15%, respectively, are among the world’s highest.

According to Dr. Hechtman, ADHD occurs in about 6 to 8% of children, 6% of adolescents and 4% of adults. However, the manifestation of this disorder changes as the individual ages. By the time a person with ADHD becomes a young adult, his or her symptoms may be harder to detect, as the ADHD sufferer learns to compensate or hide their symptoms.

ADHD, characterized by inattention, distractibility and impulsivity, has long been known as a childhood disorder, but several long-term prospective studies now show that the syndrome of ADHD persists into adulthood in about two-thirds of cases, indicated Dr. Hechtman. If ADHD goes undiagnosed and untreated in a youngster, the affected child can grow into a socially maladaptive and extremely troubled adult, with a lifetime of relationship problems, drug and alcohol abuse, and criminal activity leading to incarceration, Dr. Hechtman told her audience.

Diagnosis, a Challenge

Only a small proportion of children who have ADHD are actually treated with medication.“We still have a fair way to go to both diagnose all the children out there who have the condition and treat them. This is certainly more true of girls than it is of boys,” she added. Girls with ADHD often go undiagnosed because they tend to suffer more from the inattention component of the syndrome. “They daydream, they sit in their classrooms quietly, not bothering anyone. All too often, they miss being diagnosed until much later in life, which is very unfortunate for them,” noted Dr. Hechtman.

Great care must be taken in order to make a correct diagnosis, she cautioned. Symptoms of ADHD must be pervasive and occur in many settings; they must be persistent, lasting at least six months, and the onset must be before age seven. Importantly, the symptoms must be severe enough to affect the child’s ability to function properly in school and cause significant clinical functional impairment in social, academic and occupational endeavours. “The key phrase is significant clinical functional impairment,” she underlined.

It can be a challenge to diagnose ADHD correctly. Consequently, it is important to carry out a differential diagnosis because many conditions resemble or are associated with inattention, hyperactivity or impulsivity. Psychiatric disorders that may be similar to ADHD include anxiety, mood and adjustment disorders, learning and language deficits, psychotic disorders, and stress. Medical disorders that can mirror ADHD are developmental disorders, use of other medications such as those for asthma, substance abuse, petit mal or other seizure disorder, sleep apnea, hearing and vision problems, thyroid disorder or hypoglycemia.

Dr. Hechtman also advised clinicians to confer with the child’s teacher in diagnosing and managing ADHD. The teacher can be a great help in alerting parents and physicians to ADHD, she suggested. “Get symptoms not only from the parents, but from the teachers. Give the forms to the parents and they will get the ratings from the teacher and bring them back to you.” Teachers are good raters because they have experience with young children and know when a child is demonstrating ADHD symptoms, she added. “They see that child in a demand situation five days a week, in comparison with 30 other children, and that is an ideal observational setting. So getting teachers’ ratings is important,” Dr. Hechtman told delegates.

As complex as it may be to diagnose ADHD in children, it becomes even more of a challenge to diagnose ADHD in adults, she said. “When you see a child, he just has ADHD. But by the time you see an adolescent or adult, the ADHD is hidden because of all the other problems that have developed. So there is marked activity in the preschool era, but by the time the child is in elementary school, that activity and inattention come into play, and in addition, they have academic problems, social problems and self-esteem problems. These continue into adolescence, and these children often gravitate towards a negative peer group and begin using drugs and alcohol.” Adolescents with ADHD are prone to have more motor vehicle accidents, engage in risky, impulsive sexual behaviours, have unwanted pregnancies, contract sexually transmitted diseases and fail academically. Ultimately this downward spiral affects the adolescent’s self-esteem and he or she can develop secondary anxiety, depression or other mood disorders, indicated Dr. Hechtman.

When adolescents reach adulthood, occupational, family and legal problems arise. “It is easy to see why comorbidity increases with age in people with ADHD, and in fact, the older the person, the more hidden the underlying ADHD may be,” she explained. Employment history can be an important indication of an adult with ADHD. These adults change jobs much more frequently than adults without ADHD, some quite impulsively after a quarrel with their supervisor or co-worker; others are fired because they are difficult to get along with or are inattentive to the demands of the job, mentioned Dr. Hechtman. “In a study by Biederman [J Clin Psychiatry 2006;67(4):524-40], people with ADHD held 5.4 jobs during the past 10 years compared to 3.4 jobs for people with no ADHD (P£0.001). Among employed ADHD adults who have had more than one job in the past 10 years, 43% said they left one or more jobs because of ADHD symptoms,” she reported.

In Dr. Hechtman’s view, there is no question that pharmacological treatment is an essential part of ADHD treatment. However, she reminded her audience that medication alone is not enough. “This is an important message to take home. In our study of almost 600 children, only 31% had ADHD alone, and they were the youngest group, aged seven to nine. The rest had one or more psychiatric comorbidities. Children with many other comorbidities need more than just medical treatment.”

Abuse Potential

Parents often ask if giving their child a stimulant to treat their ADHD may ultimately put them at risk for drug abuse later in life. On the contrary, remarked Dr. Hechtman. “Reassure the parents. In one study [Biederman et al. Pediatrics 1999;104(2):E20], the overall rate of substance abuse disorders in ADHD adolescents who were treated was significantly less than in adolescents who were not treated. Medication actually prevented drug abuse because the adolescents who were treated felt better about themselves and were able to function better in school.”

According to Dr. Samuel Chang, Clinical Associate Professor of Psychiatry, University of Calgary, Alberta, an important way to limit substance abuse among this vulnerable population is to prescribe long-acting preparations. The long-acting or extended-release preparations are rarely abused, as it is too complex a procedure for the abuser (vs. the short-acting stimulants) who would need to extract the drug in a formulation which would produce euphoria.

“Long-acting or extended-release formulations, such as mixed amphetamine salts, are released in a steady state, and as a result, the patient does not experience the peaks and troughs that occur with the short-acting preparations,” he explained.

Dr. Chang stressed that short-acting stimulants are contraindicated for his substance abuse patients and he will not, under any circumstances, prescribe them because of their abuse potential.

Diversion is a much greater concern than prescription abuse in ADHD patients. “Three-fourths of users get their supply from a sibling or a friend’s prescription, so we need to educate parents on the abuse potential of prescription stimulants and exert greater control over dispensing the medications,” Dr. Chang stated. “Short-acting stimulants are more stigmatizing for the child who has to take a tablet while in school and this is another reason why I prefer not to prescribe them,” he added. Whatever medication the child is taking, the parents should always be in control. “I tell the parents to lock up the medication or take it with you if you go to work. It’s not divertible if the parent has control.”

Genetic Component

There is a very strong genetic predisposition for ADHD. According to Dr. Hechtman, there is a strong possibility that a parent who has never been diagnosed with ADHD may diagnose him or herself after their child has been diagnosed. “This often happens. The child has been diagnosed with ADHD, and then the parent comes to me and says they might also have it because they remember having trouble in school, or feeling very irritable, or that something just wasn’t right with them,” she indicated. It is now known that ADHD is a heterogeneous behavioural disorder that has multiple possible etiologies which, in addition to genetic predisposition, includes environmental factors and CNS insults. Fetal alcohol syndrome babies have a high incidence of ADHD; smoking during pregnancy has also been implicated.

Figure 1. ADHD Possible Etiologies

MRI Analyses

The neural networks of attention—the prefrontal cortex, parietal cortex, cingulated gyrus, limbic structures, basal ganglia, thalamus, brainstem and cerebellum—are all affected in ADHD, Dr. Hechtman explained. MRI studies have revealed that the frontal lobes, which are rich in dopamine receptors, the basal ganglia and the cerebellum are all smaller in individuals with ADHD compared with controls. MRI analyses have indicated a 10% decrease in the size of ADHD-associated areas. Functional imaging studies have also shown decreased striatal perfusion in ADHD patients (Swanson et al. Lancet 1998;351:429-33, Castellanos et al. Arch Gen Psychiatry 2001;58:289-95). Stimulants increase the blood flow to these parts of the brain and actually make them larger, noted Dr. Hechtman. This may be how these agents work in ADHD.

While MRI studies have shown how certain structures of the brain are involved in ADHD, MRI is While MRI studies have shown how certain structures of the brain are involved in ADHD, MRI is not a diagnostic tool, Dr. Hechtman stressed. Unfortunately, “Certain individuals are promoting MRI as a way to diagnose ADHD. Tell your patients that we aren’t there yet. MRI is not the state of the art for diagnosis.”

Practical Advice

Dr. Clive J. Schwartz, Assistant Professor of Pediatrics, University of Toronto, Ontario, offered some practical advice on how to approach children and their families when a diagnosis of ADHD is made or suspected.

One of the biggest hurdles he faces is convincing families that stimulants are “a good thing.” It is difficult for parents to understand how a stimulant medication can work for a child who is restless and inattentive. Creating an image for a concept that both child and parents can comprehend is helpful.

Dr. Schwartz gave an example linking medicine to eyeglasses to help children accept the fact that they have to take along “a tool to give them extra help in school. I tell them, ‘Note how many people in your class wear glasses. They are wearing glasses to help them adapt to the demands of the classroom. The medication does the same thing as eyeglasses, except you can’t see it. In our society, you have to switch off multi-track thinking and become focused, but you are not naturally adapted to do this. So, we are going to use a trick to help you do that.’”

He addressed listeners, “Talking in this way goes far to help a child feel less stigmatized about taking medication. Once children start doing better in school, then they are on their way to improving their self-esteem and their social skills.”

Summary

ADHD can be a challenge to diagnose. To make a correct diagnosis and institute appropriate treatment, it is essential to differentiate ADHD from other medical and psychiatric conditions. This neurobehavioural disorder has also a strong genetic component and it persists through adolescence and adulthood in a high percentage of cases. Experts here at the CPA confirmed that when determining a treatment option, long-acting preparations are an optimal strategy, as they supply a steady release of the medication in the bloodstream with less rebound, and are less likely to be abused or diverted. Above all, the appropriate treatment can help the child grow into a fully functioning adult and fulfill his or her potential.