ADHD: an update

You've just gotten that hyperactive, high-maintenance kid out from underfoot and back to school and with a sigh of relief you sit down, when the first phone call comes from the school. He's causing even greater problems in the classroom than he did at home. The teacher says it might be ADHD and perhaps you could get him assessed. Secretly you fear it's all because of your bad parenting.

Because it is so common and its treatment is controversial, this article is an update on what the evidence tells us about Attention Deficit Hyperactivity Disorder. In this article we will briefly review the current thinking on:

What is ADHD and how is it diagnosed?
How common is it?
What treatments work best?
What are the risks of drug treatments?
A final caveat
What is ADHD?
Like many complex syndromes, ADHD is probably due to more than one problem. It is thought to be a neurobiological and behavioural disorder involving areas of attention, activity level, impulse control, distractibility, and concentration.

Since several parts of the brain are responsible for these functions, delayed maturation or dysfunction in any or all of these areas could result in ADHD symptoms. Brain imaging using scans, like the PET scan, show areas of the brain that function differently in ADHD kids when compared to controls.

It is felt that the greatest area of brain involvement in this disorder is the cerebral cortex in the prefrontal area (responsible for things like inhibitions and fine judgement) with several other brain areas also involved. The brain dysfunction at least partly involves insufficient dopamine activity in these areas.

Dopamine is a neurotransmitter responsible for communication between nerve cells. Dopamine problems can result in anything from Parkinson's disease and schizophrenia to drug addiction, depending upon the part of the brain with too much or too little dopamine activity.

The diagnosis of ADHD requires a great deal of clinical skill, since the diagnostic criteria are taken from a range of common behaviours that fall along a continuum from normal to problematic.

Deciding where to draw the line between a slow-to-mature, healthy, extremely active boy and an ADHD boy can be difficult. It is essential to gather collateral information from people who see the child at school, at play, and at home.

There is no definitive diagnostic lab test to establish the diagnosis. Other conditions causing similar symptoms must be ruled out. Even performing a trial of psychostimulant medication, like Ritalin®, and watching for improvement in performance or behaviour isn't foolproof, since these medications also improve performance in non-ADHD kids (hence the Olympic ban on performance-enhancing stimulant drugs). The bottom line is to focus on function: do the child's symptoms (attention, activity, concentration, impulsivity, distractibility) significantly interfere with social, school, or recreational functioning? Does the emotional harm resulting from the child's continued failures outweigh the potential risks of labeling them with a pathological diagnosis and treating with medications with potential adverse effects? If so, then treatment is indicated.

How common is it?
The prevalence of ADHD has been found to be 3% to 5% of school-aged children. Boys are more likely to have this disorder - out of every 5 ADHD kids, 3 will be boys and 2 will be girls. Some, but not all, will outgrow their symptoms as they get older.

A little over half of ADHD children will continue to experience clinically significant symptoms into adulthood. Adult ADHD does not occur unless the adult demonstrated ADHD (manifested by significant interference with school, social, and recreational activities) in childhood.

Drug treatments
The alarm was raised in the US and Canada when rates of prescribing psychostimulants, such as methylphenidate (Ritalin®) and dextroamphetamine (Dexedrine®), and diagnoses of ADHD increased by nearly 1,000% over 5 years in the mid-nineties. Were these just burned-out teachers looking for chemical straightjackets, therapists generating customers, a massive diversion of drugs, or was it justified? Numerous well-designed studies in various parts of North America have confirmed that ADHD is not, with a few exceptions, being overdiagnosed, and that psychostimulants are not being overprescribed.

Psychostimulants are relatively safe, and some of the newer formulations allow once-daily dosing of the child in the morning. There is a risk if psychostimulants are given concurrently with one of the older types of antidepressants.

Pemoline (Cylert®), an effective, longer duration psychostimulant is to be used only after a trial of other medications, as there is a small but real risk of liver problems or even liver failure with this medication. Other medications, such as SSRIs of the Prozac® family or other antidepressants, such as bupropion (Wellbutrin®, Zyban®) or venlafaxine (Effexor®) have reported effectiveness without the addictive potential of psychostimulants.

There remains a controversy as to whether or not prescribing stimulants to children results in increased risk for adolescent or adult drug dependencies. Two large studies have reported opposite results.

Recommended treatment
There is a vast amount of research showing that, in carefully diagnosed children with ADHD severe enough to interfere with function, combining medications, including psychostimulants with behavioural therapies results in improvement in their social, recreational and school performance.

In carefully selected and monitored children, the benefits of combined pharmacologic and behavioural therapies by far outweigh the risks or potential adverse effects of therapy. Behavioural modification requires time and a lot of patience. Hang in there!

A final caveat
Pharmaceutical companies have a growing influence on what research studies are performed and which of these are reported in the literature. They generously fund medical education events at which their drug is featured.

Therapists who specialize in treating a particular disorder have an interest in seeing this condition diagnosed. The same kids who are at increased risk of ADHD are also at increased risk of substance use disorders.

So make sure you get help from a well-trained, unbiased health care professional with experience in diagnosis and treatment of children with a wide variety of mental health and behavioural problems. Don't expect a magic bullet! Parents play a vital role in practicing behavioural therapies with the ADHD child who is also receiving medication.

Some of the most creative, exciting people in the world would meet the criteria for ADHD. But they had to learn how to live in a 33 rpm world when they were designed for 78 rpm.