Acceptance has not been unanimous, though. For many of its critics, the DSM has been too unreliable, far too prescriptive and yet quite vague, very much geared towards the compartmentalization of human behaviour, very much conforming to the wishes of the big Pharmaceutical companies –in short: very problematic.
The news, then, that after more than sixty years of near hegemony –at least in the U.S.– the DSM is pushed aside by the US National Institute of Mental Health (NIMH), cannot but be welcome. A research framework is being introduced for collecting data for a new understanding of mental disorders, a "new nosology", away from DSM.
Is there, at last, room for optimism? Are we finally about to enter an era of scientific psychiatry which will (hopefully) settle all disagreements and clear out all ambiguities for good?
In the years since its first publication in 1952, the DSM has gone through four major and many minor revisions. Its latest version, DSM-IV, was published in the 90s. The new one, DSM-5, is being prepared and expected very soon.
This would be an unremarkable event for everybody not in the business, if there was not for a major, quite unexpected development.
The news is now out. On April 29, 2013, Thomas Insel, the director of NIMH, announced that the Institute "will be re-orienting its research away from DSM categories." The DSM, according to Insel, is limiting progress in mental health research. Current DSM categories "are based on a consensus about clusters of clinical symptoms, not any objective laboratory measure”. But “patients with mental disorders deserve better”. So, the NIMH is introducing a new research framework called Research Domain Criteria (RDoC). That’s just the first step. According to Insel, “we cannot design a system based on biomarkers or cognitive performance because we [still] lack the data. In this sense, RDoC is a framework for collecting the data needed for a new nosology. But it is critical to realize that we cannot succeed if we use DSM categories as the ‘gold standard’.”
What we need, writes Insel, is to adopt a new approach, beginning "with several assumptions:
- A diagnostic approach based on the biology as well as the symptoms must not be constrained by the current DSM categories,
- Mental disorders are biological disorders involving brain circuits that implicate specific domains of cognition, emotion, or behavior,
- Each level of analysis needs to be understood across a dimension of function,
- Mapping the cognitive, circuit, and genetic aspects of mental disorders will yield new and better targets for treatment."
The thing is, as science writer John Horgan commented in his blog at Scientific American, that “the NIMH is replacing the DSM definitions of mental disorders, which virtually everyone agrees are profoundly flawed, with definitions that even he admits don’t exist yet!” (his emphasis). Horgan suspects that NIMH’s decision is connected with Obama’s BRAIN Initiative, which promises to support research in the neurosciences. Yet “neuroscience still lacks an overarching paradigm; it resembles genetics before the discovery of the double helix”.
I would agree with Horgan. A question then might be raised thus: What is needed to obtain this “overarching” paradigm? Will this ever be possible?
For Thomas Insel and the NIMH, it’s just a question of time.
For Horgan, it is mainly a question of attitude: “Instead of forming fancy new programs and initiatives and alliances”, he writes, “leaders in mental health should perhaps do some humble, honest soul searching before they decide how to proceed. And they should think of what’s best not for their professions or the pharmaceutical industry but for those suffering from mental illness, who deserve better.”
But is humility and honest soul searching the only things we lack when we are talking about mental health research?
Well, we certainly lack those, but I think we also lack something more crucial.
Questions of worldview
What, I think, we lack is an understanding of what is included in assumptions as seemingly innocuous as those of the NIMH mentioned above. Assumptions always stem from a worldview and a worldview always entails more assumptions than the ones one is willing to admit. These assumptions are thought to be self-evident and taken for granted.
A scientific research programme –any scientific research programme– always reflects an underlying worldview, i.e. includes things that are taken for granted. What we lack, then, is an understanding of what constitutes a worldview –in this case the worldview of modern science.
To bring an example, the whole enterprise of modern physics is built on the premise that this world is measurable. This simply means that phenomena in the world –the decay of radioactive materials, the phases of the moon, the greenhouse effect– can be studied via their quantifiable (i.e. measurable) properties. Different phenomena, different properties, of course; but the assumption is that all phenomena have properties, and these properties can be identified and measured.
One could ask what the problem with this assumption is. I must admit: as far as physics is concerned, not much really.
But if we talk about psychiatry, things perhaps change.
Dissecting an argument
Let us recall the second of the four NIMH assumptions above:
Mental disorders are biological disorders involving brain circuits that implicate specific domains of cognition, emotion, or behavior.
This, one can easily see, is an outline of a worldview. It is not a general worldview, as such; it only refers to our psychic life; so, let’s call it a “regional worldview”.
Now, in this regional worldview, mental functioning is described in terms of brain “circuits” that implicate “domains” of cognition, emotion, or behaviour. (The actual details of this need not concern us here: they will be in the focus of the research framework the NIMH advocates.)
What we really have is an assumption that cognition, emotion or behaviour are “domains”, of similar kind –their similarity being that they can be implicated by brain “circuits”.
What is assumed further is that there is some kind of correspondence between “circuits” and “domains”. We do not need to know what sort of correspondence this is; we only need to “accept” that for any manifestation of mental life (be it cognition, emotion, or behaviour) some brain “circuits” are involved.
This leads us to conclude, together with the NIMH, that there are biological functions which represent themselves as mental functions.
And, reversely, that mental functions stem from corresponding biological functions.
The keyword here is “corresponding”.
That’s the research framework of the NIMH. Only that they are more interested in disorders, not functioning in general.
You might ask, then, where is the problem?
Well, there are three potential sources of problems.
Firstly, we have not yet established whether there is something similar between the domains of cognition, emotion and behaviour. We have only assumed it.
Secondly, the very concepts we are using (behaviour, emotion, cognition) are vague and deceptively self-evident. In fact they can refer to very different things. Consider for example the difference between being frightened because you are chased by a lion, and being frightened because you had a bad dream. The assumption here is that because in both cases we believe we have the same (subjective) emotion, namely fright, some kind of (objective) brain circuit is involved.
But crucially, we have assumed that when we say biological functions represent themselves as mental functions, the reverse is also true: mental functions stem from corresponding biological functions.
Whether these assumptions are valid or not is a huge question in its own right. And it is a question that has not yet been addressed.
Still, it's always taken for granted that mental functioning entails quantifiable phenomena that can be studied in the ways of modern science.
Does mental functioning entail quantifiable phenomena? Well, I am not so sure.
When I am frightened because the lion is after me, how much is my fear? How do we measure it? When I wake up frightened in the middle of the night because of a bad dream, how much is my fear? When a drug-induced hallucination frightens me and makes me want to harm myself, how much is my fear?
How do we measure fear? How do we measure pain? How do we measure longing? How do we measure suffering?
I am just raising the question here. I am not attempting to answer it.
But I am also trying to point out that for the NIMH such questions are not considered relevant. They are assumed to have been already settled.
In other words, the NIMH purports to begin work on collecting the “data needed for a new nosology” without really probing further on what it takes for granted.
In this way it exhibits a type of observational bias known as the Streetlight Effect: Like the drunk man of the story who lost his keys in the park at night, but is searching under the streetlight because this is where the light is, researchers conforming to NIMH's "Research Domain Criteria" will be collecting data by looking where it is easiest.
That’s not very different from what the people behind the DSM were doing all this time.
The days of the DSM seem to be numbered, but I am afraid that the new research framework does not give me many reasons to be optimistic.