Tuesday, October 14, 2008

The myths of ADHD

Over the years I have encountered many skeptics who believe neither in medicating children nor in labeling and diagnosing them. Deep, instinctual protective feelings towards children become displayed as unwavering hostility to all who prescribe psychiatric medications or attach a label to children. Anti-labeling and anti-medication becomes a lifestyle, a religious quest, an angry flag-bearing march against psychiatrists, psychologists, pharmaceutical companies, and even government-sponsored research. Books and diatribes about Ritalin nation, running on Ritalin, normal temperament, suppression of creativity, drug company conspiracies, myth of the hyperactive child, drugging into submission, medicalization of normal behavior, etc.—have all been part of the history of pediatrics and child psychiatry. More recently the attacks have broadened to include adult ADHD as well. Unfortunately there is always a grain of truth in these arguments. There is indeed over-prescribing, some children whose behavior is merely at the extreme end of the normal curve of temperament, some children whose life situations make them hyperactive and whose environments are the real problem; some who become zombies in the classroom from over-dosing, and some pharmaceutical companies who use lax criteria and exaggerate the numbers and the successes in treating with their drugs. As I suggested earlier, there is indeed some over-treatment, over-diagnosis, sloppy research, big pharma skullduggery in collaboration with corrupt researchers—matters well-covered in the media and in blogs by reputable critics (see especially the blogs on the subject by Barney Carroll). But the real world is complicated. Science may take a while to catch up with flawed opinions floating about in peoples' heads as if they were fact. We now know that there is also a degree of reality behind the diagnoses, brilliant successes with some of the treatments, justification for early interventions; that there are multiple genetic and environmental risk factors associated with many childhood psychiatric conditions. Though not ready for clinical use as yet, and notwithstanding the excesses by fraudulent practitioners of neurofeedback or brain scanning, there are nevertheless sound neuroscience advances at all levels that attest to the reality of conditions like ADHD; true diseases whose definitions are based in the genetics, biochemistry, brain morphology, and physiology of modern science. I also believe that there are many honest collaborations between pharmaceutical companies and rigorous scientists that have made tremendous progress possible in therapeutics and basic knowledge about psychiatric illness in children. That transparency and close oversight are needed in those collaborations seems obvious as well. I am prompted to bring these issues up because I recently read what I think is the most convincing and brilliant conversion by a standard critic into a more thoughtful advocate for appropriate diagnosis and treatment: the blog by Judith Warner, which I highly recommend: http://warner.blogs.nytimes.com/2007/03/01/second-thoughts/ There are many brilliant and thoughtful observers out there who have been self-assured critics of ADHD, thinking it all a set of myths, until they have such a child themselves, or run face to face with these children in the lives of family or friends. The more brilliant the opposition, the more stunning the conversion to the reality.

Wednesday, October 8, 2008

How many ADHD children and adults are out there?

My mentor, Leon Eisenberg, once commented that when we started out in the 1960's studying "hyperactive children" --now called ADHD--it was hard to convince anyone that they really existed or that it mattered. Especially doubtful were the British, led by their great scholar Michael Rutter. Now the schools and homes seem to be flooded by them, to the point of an epidemic. Although my old colleague Paul Wender, also at Hopkins in the 1960's, had first alleged that adults also had ADHD, nobody took that idea seriously until recently. Now there is a claim that their prevalence even exceeds the 2 to 3 percent of child ADHD, and over the last 5 years their prevalence has steadily and rapidly increased.

 Recently the National Comorbidity Survey of the World Health Organization (WHO) under Harvard scholar, Ron Kessler, has placed the figure at 4 to 5 percent whereas the estimates for childhood ADHD average around 2 to 4 percent. What gives? Can there be more adult ADHD than child ADHD?

 First, there are now dozens of studies throughout the world that consistently place childhood ADHD as high as 10 percent of the population, and averaging round 4 to 6 percent. Are there really 10 kids out of a hundred with ADHD (3 or 4 in every average classroom)? Well how does one KNOW? Remember that these studies usually involve hundreds or thousands of children, so that defining a case cannot usually involve individual clinical interviews. Instead, they may involve telephone surveys, checklists of symptoms, or surveys of parents.

Remember too, that according to the standard psychiatric definition (the Diagnostic and Statistical Manual of the American Psychiatric Association, now in its 4th revision, called DSM-4), there are 5 criteria that must be met. The most important of those criteria is the one that requires that the symptoms not be better explained by some other illness; that is, a "differential diagnosis" must be made. If it's autism, or depression, or anxiety, etc., then the 18 ADHD symptoms could be caused by one of these other illnesses.

But wait! Doesn't that mean you have to do a COMPLETE psychiatric examination? If you don't then the presumed "case" of ADHD could be something else, and the total count of ADHD cases would include all the other possible diagnostic contenders. Now examining all of the epidemiological studies of ADHD, the only one that I know of that actually used a complete diagnostic interview on enough children to form a reliable prevalence estimate was a study by Adrian Angold and Jane Costello in the Western counties of North Carolina. Their prevalence rate for ADHD: less than 2 percent. Incidentally, they found that a great many children who did NOT meet ADHD criteria were being treated for it, and a great many who DID meet criteria were not being treated for it. Obviously a correct diagnosis is necessary to avoid both kinds of mistakes. Wow! ADHD IS BOTH UNDERESTIMATED AND OVERESTIMATED at the same time, and they are being unter-treated and over-treated at the same time.

 Now what about the adults? The big problem here is that there are no agreed-upon criteria for adult ADHD, though there is much work being done to alter the criteria to account for developmental changes in symptomatology, age of onset, and types of impairment associated with the condition. DSM-V will undoubtedly give us the basis for a real epidemiologic survey. However, the afore-mentioned WHO study started with a subsample of the very large survey carried out around the world, and by using statistical methods (e.g. imputing the actual numbers for the whole sample from a smaller subsample), they used 6 symptoms that were included in the original survey, to arrive at a prevalence estimate for adult ADHD, based on followup telephone interviews of the smaller subsample. The result: 4 to 6 percent prevalence of adult ADHD.

 Here again, there really is no full psychiatric interview, so that in my mind these high figures must remain suspect. Incidentally, I am not reassured by the fact that this "WHO Study", which I participated in, was sponsored in part by a drug company, and that shortly after the first findings the drug company was using the 6 symptoms as a diagnostic guide for recommending adults to see their physician for possible treatment. So here we have another possible explanation of the explosive growth of adult ADHD: it is a boon for pharmaceutical companies who are now virtually all scrambling to get FDA approval for ADHD drugs in children to be approved for adults as well.

 Don't get me wrong; adult ADHD is a real problem, and one that can be successfully treated by medication and other methods, and is a condition that has serious consequences for the patient and their families. But if ADHD, as we and most scientists agree, is a developmental problem starting early in life, then it seems unlikely that the true prevalence for adults can be more than the prevalence for children. Adults will pass through the age of risk for many other psychiatric and emotional conditions than is the case for children, so that they will have more comorbidities and more impact on their adult lives than they did as children. On the whole they could be sicker, though many compensate or adjust to their illness, especially those well-treated as children. But it is precisely these other conditions which might better explain their illness and dysfunctions, so they may be mis-diagnosed as ADHD when they are not ADHD cases at all, just as many children have likewise been mis-diagnosed because their symtoms could be due to other disorders that were not screened for. The bottom line: SYMPTOMS ALONE CANNOT MAKE A TRUE DIAGNOSIS.  It is a mistake to make the diagnosis without carefully ruling out other explanations. To do this requires a sound clinical interview by a trained mental health professional.