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Prescription Drug Information for Canadians


The Management of Attention Deficit Disorder

Gabor Mate M.D.

(Dr. Mate is a Vancouver physician, writer and psychotherapist who himself has been diagnosed with ADD. He belives in a holistic approach to treatment. This includes medication as well as social, familial and emotional factors.)

Pharmacists are in a key position when it comes to the treatment of attention deficit disorder. The usually prescribed medications are somewhat tricky to use. Not a11 physicians are familiar with just how individualized and specific doses and schedules need to be. Patients also need to be counseled about side effects, which is another area sometimes neglected in medical practice. The following is a brief description of ADD and its pharmacological treatment.

Disease of the next century of flavour of the nineties? Attention Deficit (Hyperactivity) Disorder excites controversy not only as to its treatment but even as to its very legitimacy as a diagnosis. There is no doubt that ADD has reached cult status in some circles. There is also no doubt it exists, is as objectively diagnosable as many other conditions in medicine, and responds positively to judicious treatment.

In brief, the DSM-IV criteria for diagnosis rest upon signs and symptoms of poor attention span for low interest activities, easy distractibility, an automatic and distressing propensity to "tune out," low frustration tolerance, and impulsiveness. Hyperactivity may or may not be present. These criteria had to have been present from no later than the earliest school years.

It used to be thought that people "grow out" of ADD. Perhaps some do. Most people, in this writer's opinion, do not grow out of ADD, they just grow out of school.

The commonest mistake leading to non-diagnosis is the belief that the poor attention span must extend to all activities. On the contrary, the child or adult with ADD may even hyperfocus on activities of heightened interest, to the point of losing awareness of time, the environment and other plans and priorities. In all but the most severe cases the symptoms are situational, that is. driven or exacerbated by what are called "maintaining factors" in some environments, calmed and softened in others.

While there is no single objective diagnostic tool yet available, there is convincing proof that AD(H)D has a definite neurophysiological and biochemical dimension. By means of PET scans. cerebral glucose metabolism in adults with childhood-onset hyperactivity has been shown to be lower than that of controls during the performance of directed tasks. (Zametkin et. al., NEMJ. 323,1361-I366. ) The difference was most prominently observable in the prefrontal (orbitofrontal) and premotor areas, where the coordination of attention and motor activity are centered. In a study performed at the University of Alberta, pre-adolescent boys with ADD have been shown to have similar EEG's to controls while tested at rest, but to exhibit increased slow wave activity during directed tasks. (Biofeedback and Self Regulation, Vol. 20, No. I,1995)

The most impressive evidence of the biochemical/neurophysiological aspects of ADD is the response of properly diagnosed patients to psychostimulant medication. People who have not been able to sit still all their lives are all of a sudden able to focus and to function without distractibility and fidgetiness. Patients feel calmer, more in control of their formerly perpetual motion-machine minds.

Methylphenidate (Ritalin), dextroamphetamine (Dexedrine) and the other psychostimulants are thought to work by increasing the availability of the neurotransmitter dopamine in the attentional centres of the brain. They are thought to act by inhibiting the uptake of dopamine and norepinehprine by the presynaptic neuron and by increasing their release into the extraneuronal space. Their action can most simply be understood by considering that in ADD the centres that modulate attention and self regulation are understimulated and therefore do not adequately perform their task of inhibiting impulses and the myriad of sense impressions and emotional stimuli that reach the cortex. The psychostimulants stimulate inhibition, thereby exerting a calming and focusing effect.

This would naturally explain the well-known propensity of methylphenidate to turn children into "zombies." It is not the fault of the prescription but of the prescriber. Too much stimulation of inhibition will lead to overinhibition.

The goals of pharmacologic treatment, the end point, cannot be behaviour control to suit the needs and desires of parents or teachers. If that were the issue one may as well drug children with benzodiazepines. The goal is to enhance the ability of the child (or adult) to focus, to stay on task, and to reduce the impulsiveness which creates for the individual a multitude of problems and contributes to social isolation and low self esteem.

There can be no formulaic dosing with the psychostimulants. Although generally the maximum dose with methylphenidate will be 1 mg/kg/day, one rarely has a need to go that high We cannot apply dose-to-weight criteria in prescribing. Patients will vary in their response to medication, regardless of size. The best policy is to begin with a very low dose and to build up gradually over a period of a week or two, allowing response and side-effects to set to upper and lower limits of dosing. The experience of the individual patient is the best guide to dosages. In general, dextroamphetamine will require about half to three quarters of the dose of methylphenidate. Some patients will respond better to one drug or the other, so in case of treatment failure it is legitimate to switch to the alternative.

Both medications come in short-acting and time-release preparations. Often one will combine short- and long-acting forms of the same medication.

There have been many studies showing short-term benefit from the use of psychostimulants. One meta-analysis, in 1977, reported up to 77% improvement in children, with up to 39% for placebos. A more recent study in adults compared the effects of methylphenidate with the effects of placebo drugs. There was a marked 78% improvement in the MPH group, compared with 4% for placebo. (Spencer et. al., Archives of General Psychiatry, 52,1995. ) There is no evidence that there are long-term benefits on the target symptoms once the medications are stopped. (The studies regarding the effects of psychostimulants on cognitional factors such as memory, vigilance, attention, concentration and learning, on academic achievement, and on behavior are reviewed in Barkley, Chapter I 7, and in Nudeau, Chapter 10.)

The medications have been around since the 1930 and 1940's, that is, for five or ten or twenty times as long as some other medications we currently prescribe. Serious side-effects, such as tradeoff dyskinesia are extremely rare: one is unlikely to see them. Common adverse effects include loss of appetite (often temporary and usually manageable), sleep disturbances, mild abdominal pain, headache, and nausea. Some patients will experience heightened anxiety and even panic, while others may experience depression. Most side-effects are self limited and all will resolve within a day or two, or even less, of stopping the medication. To be watched for is the appearance or exacerbations of tics.

There is no evidence that long-term use leads to addiction; on the contrary, an excellent case can be made that timely prescription of the psychostimulants will prevent drug abuse by obviating the need for self medication with illicit drugs such as cannabis or cocaine which do have a positive effect on ADD symptoms in the short term but expose the individual to great risks in the long term.

Some anti-depressants, particularly desipramine (Norpramine) and venlafaxine (Effexor). can be used as alternatives to psychostimulants in a significant number of cases. Even better, according to some data (and in this presenter's own personal experience), is bupropion (Wellbutrin.) (J.Am. Acad. Child Adolesc. Psychiatry, 34: 5,1995).

Under no circumstances should pharmacology be the only or even the dominant modality of treatment in either child or adult. In all cases the physical and emotional environment need to be examined and adjusted. Quite often the hyper-sensitive ADD child acts as the unwitting marker for family dysfunction well beyond his control. Nutrition and other so-called life style factors must be given rigorous attention.

Selected References

The Attending Physician: Attention Deficit Disorder A Guide for Pediatricians and Family Physicians

Copps, Stephen C., M.D.

SPI Press,1992

Attention-Deficit Hyperactivity Disorder in Adults

Wender, Paul H., M.D.

Oxford University Press,1995

A Comprehensive Guide to Attention Deficit in Adults: Research, Diagnosis, Treatment

Nadeau, Kathleen G. (Ed.)

Brunner/Mazel,1995

Attention Hyperactivity Disorder: A Handbook of Diagnosis and Treatment

Barkley, Russell A.

The Guildford Press

1990

Medications for Attention Disorders (ADHD/ADD) and Related Medical Problems (Tourette 's Syndrome, Sleep Apnea, Seizure Disorders): A Comprehensive Handbook

Copeland, Edna D., Ph.D. with Copps, Stephen C., M.D.

Specialty Press Inc.,1995

Driven to Distraction: Recognizing and Coping with Attention Deficit Disorder from Childhood Through Adulthood

Hallowell, Edward M., M.D. and Ratey, John J., M.D.

Touchstone,1994

Answers to Distraction

Hallowell, Edward M., M.D. and Ratey, John J., M.D.

Pantheon Books,1994

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