Overdiagnosis in psychiatry occurs where patients are identified with a mental disorder when they do not have significant impairment and would not be expected to benefit from treatment. These problems can arise even when diagnostic criteria are met, that is, in the presence of milder symptoms that fall close to, or within, a normal range on a diagnostic spectrum. Overdiagnosis can lead to unnecessary labelling, unneeded tests, unnecessary therapies, and inflated health care costs. In medicine, with the best of intentions, practice has come to favour more tests and more treatments, all of which tend to drive overdiagnosis. This problem may be worsened by a prevailing cultural ethos that more is better.

Outside of psychiatry, there are clear examples of overdiagnosis. For example, screening programs designed to detect early stages of certain cancers appear to increase incidence estimates, but may have no discernable effect on mortality…

Psychiatry has followed this trend. It has been estimated that at least 40% to 50% of the population will meet criteria for at least 1 psychiatric diagnosis during their lifetime. The current system of nosology in psychiatry, based on phenomenology, that is, subjective reports and clinical observations, encourages overdiagnosis. The presence or absence of mental disorders is not defined by biomarkers, allowing diagnostic constructs to describe broad spectra that cross over into normality.

So begins a short, sharp article on overdiagnosis in psychiatry that has just been published. The authors raise significant issues about psychiatry in general and adult ADHD in particular – they argue that the DSM diagnosis is flawed and impractical; they take aim at patients (yes, patients); they then turn their sites on researchers and industry.

The comments of sensational journalists? The skewed opinion of Scientologists on a blog? Actually, the Reading comes from the pages of The Canadian Journal of Psychiatry and, for the record, the paper’s first author is one of the most prominent psychiatrists in the country; Dr. Joel Paris is the past chair of McGill’s Department of Psychiatry and the author of more than a dozen books.

This week’s Reading: “Is Adult Attention-Deficit Hyperactivity Disorder Being Overdiagnosed?” by Paris et al.

Here’s the link:

http://www.ncbi.nlm.nih.gov/pubmed/26175391

The Canadian Journal of Psychiatry has always been worth reading, but its new editor, Dr. Scott Patten, has taken this journal to the next level. And, in my opinion, this “perspective” paper is a must-read – one of the most important papers written this year.

Dr. Joel Paris

On this we can all agree: childhood ADHD isn’t necessarily outgrown. Paris et al. argue, though, that the diagnosis of adult ADHD is deeply problematic.

Consider the points they raise about prescribing habits:

· A Journal of Clinical Psychiatry survey reported a 6-fold increase in the portion of US psychiatry office visits in which adult patients were prescribed a stimulant between 1994 and 2009.

· Among non-psychiatrists, the portion was even higher: an 8-fold increase.

· A British paper found a doubling of prescription rates between 2004 and 2009 in the UK.

A rapidly increasing frequency of a once-rare condition may reflect increased recognition, but may also constitute a diagnostic epidemic.

Disappointingly, Paris et al. note almost nothing is written on the topic – a PubMed search yielded just three papers on overdiagnosis. (In contrast, consider that my Google search of “adult ADHD” yielded more than 35 million hits, or about 50% more than “Schizophrenia.” The second hit, by the way, is a site funded by a drug company.)

How did we get here? Paris et al. note several significant problems, starting with the very definition of this disorder.

The DSM-5 criteria for adult ADHD are so broad that they fail to distinguish between illness and normal variation. But even if we were to accept these criteria as valid, the current definition is heterogeneous. It is well established that childhood ADHD responds best to stimulants when hyperactivity is most prominent, whereas inattentive symptoms are less responsive. That suggests that ADHD, both in children and adults, is a syndrome, not a biologically distinct disease. This conclusion is supported by high comorbidity, a variable course, and a variable response to treatment. These variations might best be viewed as identifying subgroups rather than additional diagnoses.

Paris et al. note further problems in diagnosing individuals. Comorbid conditions may mimic ADHD symptoms, and the DSM-5 definition requires an onset of symptoms before the age of 12 – challenging for clinicians to establish.

But what makes the piece so compelling is that they push further, listing out various factors that go beyond the DSM-5.

Medicalizing Attention: “Society increasingly demands a high level of performance on tasks that require sustained attention and multitasking. Thus social forces, such as competition in school settings, can motivate patients to seek stimulant prescriptions, which, in turn, require a diagnosis of ADHD.”

Disability Benefits: “Receiving a diagnosis of ADHD may make it possible for some adults to be considered disabled, and to receive benefits.”

They then outline two non-patient factors: First, researchers have an incentive to overdiagnose in an effort to win grants. Second, pharmaceutical companies aggressively market the diagnosis (and treatment) to maximize profit.

Paris et al. conclude their paper by urging caution. They suggest that clinicians make more effort to get collateral before making a diagnosis; they argue for more research in the field.

Like every good paper, they end up raising more questions than they answer. How did we get here? Moving forward, how do we prevent overdiagnosis in the future? These questions aren’t simply academic. Overdiagnosis does damage – not simply because it leads to overtreatment, but because it damages the fragile reputation of our field.

Let’s return to Paris et al.’s point about pharmaceutical companies. The New York Times ran a hard-hitting piece on “The Selling of Attention Deficit Disorder,” noting drug companies employed particularly aggressive tactics – and enjoyed great success. As the article notes, drawing on IMS Health data, stimulant sales quintupled in the US between 2002 and 2012. (!)

Does this demand a public policy solution? It’s difficult to see a law that would require a clinician to, say, delve through elementary school report cards before making a diagnosis. But what about sunshine laws, forcing clinicians to disclose compensation from drug companies? Would this bring needed accountability? Would this instead see valuable clinical hours lost to paperwork and meetings with accountants? That’s a topic worthy of its own future Reading.

Further Reading

Find “The Selling of Attention Deficit Disorder,” here:

http://www.nytimes.com/2013/12/15/health/the-selling-of-attention-deficit-disorder.html?pagewanted=all

Reading of the Week. Every week I pick a reading — often an article or a paper — from the world of Psychiatry.