Schizophrenia Doesn't Exist!?

Water

Source: Giuseppe Arcimboldo/Public domain

Last month, an article written by Dr. Jim van Os, a psychiatrist at Maastricht University in the Netherlands, appeared in the British Medical Journal with the provocative claim that “‘schizophrenia’ does not exist.”¹

The op-ed piece, published as a “Personal View,” was picked up in in the popular science press with the headline, “‘Schizophrenia’ does not exist, argues expert.” While the popular press article enjoyed only limited release, it was published widely enough that I saw it cited by various online commenters as evidence that “there’s no such thing as schizophrenia” and by implication “there’s no such thing as mental illness.”

Before we jump to wild conclusions like that, let’s take a closer look at what Dr. van Os is really saying too see what it might mean that schizophrenia doesn’t exist, but also that it does.

To begin with, it should be acknowledged that Dr. van Os is a well-respected psychiatric researcher who is a bone fide expert on psychosis. His work has in particular demonstrated the presence of psychotic experiences such as voice-hearing or delusional thinking among people “in the community” who aren’t in psychiatric treatment or don’t necessarily have a mental illness.² His research has therefore been a major contributor to the idea that psychosis exists on a kind “spectrum,” distributed along a continuum of severity, impairment, clinical concern, and need for intervention.

Consequently, when Dr. van Os writes that “’schizophrenia’ does not exist,” taking care to place quotation marks around “schizophrenia,” what he’s mainly saying is that the term “schizophrenia” doesn’t represent a single disease entity and should therefore be replaced with “something like ‘psychosis spectrum syndrome.’”¹

In fact, that’s neither a radical nor a novel proposition. The psychiatrist who originally coined the term “schizophrenia,” Eugen Bleuler, said the very same thing more than a century ago. Bleuler, a dedicated clinician, spent countless hours with his patients and in recognition of the diversity of their experiences, proposed that schizophrenia wasn’t a single disease, but a “whole group” of schizophrenias. His classic text on the subject was even titled, Dementia Praecox or The Group of Schizophrenias. This heterogeneity has been built into the criteria for schizophrenia outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which based on the need for only a few psychotic symptoms for diagnosis, allows that two individuals with schizophrenia could look very different.

But saying that “schizophrenia” represents a variety of distinct disorders with different causes doesn’t mean that it doesn’t exist at all. To understand why, let’s break down what we mean when we talk about a “psychosis (or any other disease) spectrum.” First, let’s consider a more familiar example of a spectrum from science: the visible light spectrum. Electromagnetic radiation exists on a continuum that varies in frequency and wavelength, with the visible light spectrum representing radiation whose wavelengths comprise a more narrow range of roughly 400-700 nanometers. The different wavelengths within this range are perceived by the human eye and brain as different colors like red, orange, yellow, green, blue, and indigo. Likewise, individual colors themselves—like green—can be characterized as dark green, light green, or blue/green (turquoise).

By way of analogy, we can then think of electromagnetic radiation as the continuum of mental health and mental illness, the visible light spectrum as psychosis, and the color green as schizophrenia. So, when psychiatrists talk about a “spectrum of psychosis,” we mean that psychosis is a kind of identifiable brain experience that can span a continuum of quantifiable severity, ranging from the distressing and functionally impairing symptoms of a mental disorder to the unusual but potentially normal experiences of people without mental illness. When we talk about a disorder like schizophrenia, we’re talking about a recognizable form of psychosis that, like the color green, exists within the psychosis continuum and can itself span a continuum of severity. To say that schizophrenia isn’t any one thing or that its definitional boundaries are fuzzy doesn’t mean that it doesn’t exist, anymore than we could credibly claim that “green” doesn’t exist. The same could be said of “planets,” “cars,” or “pain.”

This is a subject I’ve addressed in my own academic work:

“Although it is practical and perhaps reassuring to think of mental disorders as discrete entities or “natural kinds,” existing evidence supports a continuum between mental illness and mental health with indistinct borders. Even the DSM-IV concedes that ‘there is no assumption that each category of mental disorder is a completely discrete entity with absolute boundaries dividing it from other mental disorders or from no mental disorder.’ However, this lack of discrete boundaries does not mean that there is no such thing as mental illness [or schizophrenia], or that the boundaries are completely arbitrary.”³

I’ve likewise written about the apparent conflict between categorical approaches to psychiatric diagnosis (the idea that psychiatric disorders are discrete entities) and the kind of “spectral” or “dimensional” approach for which Dr. van Os advocates, arguing that the two need not be mutually exclusive:

“While seemingly contradictory, [the] duality between category and continuum is present throughout medicine, whether in hypertension (where there is now “prehypertension”), cancer (where there is carcinoma in situ), and even debates about what constitutes life and death. In fact, while human perception is particularly adept at contriving patterns and boundaries in “things,” the reality is that most “things” can be conceptualized along both categorical and dimensional terms, as with the “particle” and “wave” duality of light.”⁴

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"Incorporation of a dimensional model, “based on quantification of attributes rather than the assignment to categories” was considered for DSM-IV, but the idea was eventually abandoned due to “serious limitations,” including the belief that categorical boundaries are vital to clinical decision-making.”⁵

In other words, there are relative advantages and disadvantages to thinking of psychiatric disorders as either categories or continua. Categorical classification systems or “nosologies” are often favored for ease of communication and to guide decisions that require threshold definitions (e.g. when to treat or not treat a disorder), while continuous approaches better account for diversity and variation within a given category. The utility of one approach doesn’t invalidate the other.

Beyond the idea that schizophrenia probably represents one word but many disorders, Dr. van Os also argues that the term “schizophrenia” should be dropped because the term is equated with a “devastating” and “hopeless chronic brain disease” with a much poorer prognosis than the more subtler or milder forms of psychosis detected in his own research.¹ Here again, the assertion that the natural course of schizophrenia is variable would be best credited to Bleuler a hundred years ago. In coining the term “schizophrenia” (loosely translated as “split mind/soul/spirit”), he intended to move beyond the previously-used term “dementia praecox” (literally, “precocious dementia”) that emphasized a more deteriorative course of illness in favor of a “less static and stigmatizing” term that highlighted the fractioning of different psychological functions and aspects of personality.⁶

That’s not to say that the term “schizophrenia” isn’t stigmatizing. It is. But inventing a new name for something that’s stigmatized runs the risk of turning into what psychologist Stephen Pinker calls a “euphemism treadmill.” As I wrote in a previous post called “Rebranding Psychiatry: Euphemisms, Stigma, and Progress:”

“…changing the name for schizophrenia would probably not fix its association with stigma because “the stigma associated with schizophrenia arises mainly because of our inability to treat it effectively” rather than because of the name itself. In other words, the best remedy to erase stigma associated with a mental illness is to improve its treatment and in doing so remove associations with poor functioning and low prospects of recovery. Inasmuch as that is possible, it would go a much longer way towards combating stigma than changing names ever could.

Nonetheless, some countries have forged ahead in abandoning the term “schizophrenia” in an attempt to combat stigma. For example, in Japan, after much debate, the Japanese Society of Psychiatry and Neurology replaced the old term for schizophrenia, “seishin-buretsu-byo” (“mind-split-disease”) with a new term “togo-shitcho-sho” (“integration disorder”). While preliminary surveys suggested that name changes like this can indeed reduce stigma, it may be that any such benefits reflect only temporary ignorance about a new term, with old stigma becoming associated with the new name in time. Simply finding a new name for the same thing may have limited utility in changing people’s negative attitudes, with new euphemisms inevitably becoming dysphemisms in an endless cycle.”

Stigma aside, Dr. van Os also argues that we should also abandon the term “schizophrenia” because it detracts from attention to other psychotic disorders that represent “70% of psychosis morbidity,” yet are less well-recognized “as if they don’t exist.”¹ But this is a puzzling argument. While he suggests that “only 30% of people with psychotic disorder have symptoms that meet the criteria for schizophrenia,” his claim that other psychotic disorders including delusional disorder, schizophreniform disorder, and brief psychotic disorder “constitute 70% of psychotic illness morbidity” misses the mark. Schizophrenia, lying at the more severe end of the psychosis spectrum, warrants the attention it receives because it’s responsible for a disproportionate amount of morbidity in the form of functional impairment and need for care. As the most easily recognizable and debilitating form of psychosis, schizophrenia deserves its own name. In contrast, some of the other disorders that Dr. van Os thinks deserve more attention are self-limited (e.g., schiophreniform disorder and brief psychotic disorder), while the kind of psychotic symptoms that his research has detected “in the community” often don’t represent mental disorder at all.

One of the disadvantages of conceptualizing psychosis as a spectrum is that it can encourage the very thing that Dr. van Os seems to want to avoid – lumping psychosis together with a kind of “one size fits all” mentality. This has the potential to go awry in different directions, by inappropriately conflating severe disorders with those that are more mild and mild disorders with those that are severe. Dr. van Os wants to get rid of “schizophrenia” because he doesn’t want to see the term inappropriately applied those with milder forms of psychosis. I couldn’t agree more and have said so—properly used, schizophrenia shouldn’t be applied as lazy and loose label for all forms of psychosis, just as treatments like antipsychotic medications that are effective for schizophrenia shouldn’t be assumed to be the best intervention for other psychotic conditions for which they haven’t been well-studied.^3,5

But keeping schizophrenia as a categorical diagnosis could help to preserve milder disorders as distinct in real and meaningful ways. When DSM-5 eliminated the term “Asperger’s Disorder” in favor of “Autistic Spectrum Disorder,” advocacy groups were up in arms because “Aspies” had suddenly lost their special status as an example of “neurodiversity” as opposed to merely part of a large spectrum of more clearly pathological autism. Adopting a “psychosis spectrum syndrome” could do the same to those with milder forms of psychosis.

In practice, a spectral view of psychosis could end up being far more likely to pathologize than to destigmatize, with a greater potential for inappropriate diagnosis and treatment. It has been argued for example that this is exactly what has happened with bipolar spectrum disorders,⁷ where wanton antipsychotic treatment of irritable depressions has now become the rule. If you’re the kind of person that wants to argue that mental illness doesn’t exist and that psychiatrists are guilty of overdiagnosis and overtreatment, citing Dr. van Os’ headline that “’schizophrenia’ does not exist” is therefore precisely the wrong way to go about doing it.

At the same time, adopting a spectrum view of psychosis just as easily risks inappropriately applying assumptions about mild psychotic symptoms—like that treatment isn’t needed or that it might just go away—to severe conditions like schizophrenia. This is a serious concern that has recently arisen in response to efforts to "romanticize psychosis" that I addressed in a previous post called “Psychosis Sucks!”

Finally, let’s take a quick, parting look at Dr. van Os’ complaint that schizophrenia is described by the American Psychiatric Association as a “chronic brain disorder” that is “highly heritable” with “predominantly genetic risk factors.” He doesn’t quite go so far as to say that this is wrong, though certainly other naysayers have done so, pointing a finger at the outdated fiction of a “chemical imbalance” being the cause of schizophrenia. Still, despite the idea of schizophrenia as a group of different disorders, it does appear to be highly heritable, with the greatest predictor of schizophrenia having an identical twin or a 1st-degree relative with the disorder (50% and 10% risk respectively). In 2015, a research group re-examined genetic data from existing genome-wide association studies, operating on the assumption that if schizophrenia is indeed a group of disorders, then clusters of small genetic differences called single-nucleotide polymorphisms (SNPs) might be associated with different subsets of psychotic symptoms that themselves cluster in certain people with schizophrenia.⁸ The authors reported that 42 different sets of SNPs sets accounted for 70% or more of the risk of schizophrenia, with certain genetic variations conferring as much as a 100% risk of schizophrenia among those with specific types of psychotic symptoms.

In a similar vein, another paper published earlier this year that was carried widely in the popular press revealed how there could be many possible genetic pathways culminating in a common biological mechanism for schizophrenia called excessive synaptic pruning in which too many connections between brain cells are pruned away during adolescence.⁹ Although the synaptic pruning hypothesis isn’t new, the study revealed how multiple SNPs that are associated with schizophrenia can affect the structure of genes in mice encoding a protein called complement component 4 that activates pruning in mice. This offers an attractive model for how multiple genetic abnormalities might converge on a common explanation for schizophrenia. Taken together, these two studies suggest that for all the shortcomings of modeling schizophrenia as a single disease entity, psychiatric research may indeed be hot on the trail of biological explanations that can account for both the heterogeneity of the “group of schizophrenias” as well as unifying symptoms and causal explanations.

In the end then, the argument that “schizophrenia” doesn’t exist is far from compelling. Schizophrenia is a word we use in medicine to describe a familiar set of co-occurring psychotic symptoms, with potentially different causes, just like “anemia,” or “hypertension,” or “headache.” In some cases, it can be useful to think of it as a categorical disorder, distinct from other forms of psychosis. In others, it can be best thought of as a spectrum condition, lumping it together with other psychotic disorders. A more enlightened view of schizophrenia acknowledges that both can be true.

Dr. Joe Pierre and Psych Unseen can be followed on Twitter here. To check out some of my fiction, click here to read the short story "Thermidor," published in Westwind earlier this year.