what exactly is a mental disorder, and what does it mean to have one? This is the central question addressed by this book.
In order to develop effective treatments for mental disorders, we should ideally be working from a good understanding of how exactly they emerge and persist; i.e., we must have good explanations of mental disorders. Further, due to their complexity, developing such explanations necessitates reasonably coordinated action by researchers around the globe. Before it will be possible to explain mental disorders effectively then, there will likely need to be common sets of labels and concepts that ensure that researchers are seeking to explain the same things, i.e., we must have ways of classifying mental disorders1. These three tasks—classification, explanation, and treatment—are often seen as the three core tasks of psychopathology research.
The classification of psychopathology is currently at a conceptual crossroads. It is increasingly becoming accepted that fundamental flaws in the DSM-ICD are resulting in it struggling to pick out ‘real’ mental disorders as opposed to artificially selected clusters of symptoms
Theoretical work within the field of classification is currently asking important questions such as: should our diagnostic systems simply give labels to patterns of signs and symptoms, or try to map onto the causal structures underlying disorder?; should our diagnostic systems attempt to be theoretically neutral, or be open and honest with their theoretical commitments?; are mental disorders simply brain disorders?
The task of explanation meanwhile, is concerned with the postulation and validation of theories that make the behaviors and experiences observed in mental disorders less surprising and more comprehendible
The task of explanation meanwhile, is concerned with the postulation and validation of theories that make the behaviors and experiences observed in mental disorders less surprising and more comprehendible (Haig, 2014). Whether grounded in neuroscience, psychology, or some other discipline, good explanations of mental disorder point to opportunities for treatment by tracking factors that either cause or maintain mental disorder. Current and historic attempts at explanation in psychopathology have resulted in limited success. To illustrate this point very briefly, compare current understanding of the causal processes involved in bio-medical illnesses such as the flu or cancers, to prototypical mental disorders such as depression and schizophrenia. We may not have ‘cures’ for any of these problems, but at least within the bio-medical examples we have some clear ideas about what is going on—i.e., infection by an influenza virus and the uncontrolled division of cells due to mechanisms that are coming to be understood. Comparatively, almost all mental disorders lack agreed-upon causal structures
One of the founding observations of the current project is that this three-task model of psychopathology is incomplete. The elementary yet missing question seems to be: What is mental disorder in the first place? Before we can classify mental disorders—or explain and treat them—we must have some concept of what counts as a mental disorder, why this is the case, and what sort of things they are. What we take mental disorder to be, either explicitly or implicitly, directly informs how we go about the tasks of classification, explanation, and treatment. Our understanding of the nature of mental disorders is a metaphysical commitment (read: ‘educated starting guess’) that will bias our epistemological strategies, such as how we go about designing studies and reasoning about their findings (Hochstein, 2019).
are mental disorders something you get or something you do? In other words, does somebody ‘have’ depression or are they themselves depressed? This question is important because it has direct implications for how society and individuals, respond to someone experiencing/having/enacting a mental disorder
does a mental disorder exist inside someone’s brain or is it dispersed across their brain, body and environment?
are mental disorders defined by brute facts or by social norms and values?
If, however, mental disorders are not based on social norms and values, instead picking out ‘real’ states or entities in the world, what exactly are they? Are genuine mental disorders required to be diseases or brain abnormalities, or may they be a different kind of thing entirely?
the purposes of both science and natural philosophy are to explain the world around us. It therefore makes just as much sense to me to consider science a branch of natural philosophy that has particularly well-developed empirical muscles, as it does to consider natural philosophy a kind of science with particularly well developed analytical/theoretical muscles.
A primary observation that motivated the current project is that the concept of mental disorder that an individual subscribes to tends to track the individual’s conception of human functioning in general. Put more simply, someone’s implicit or explicit understanding of how the human mind works seems to inform their understanding of the human mind as not working properly
there is significant room for improvement in the conceptual understanding of mental disorders
the philosophical orientation known as 3e cognition or enactivism seems to be a good candidate for this role as a guiding framework of human functioning within psychopathology
3e cognition is a perspective on human functioning and ‘how the mind works’ that allows for the integration of biological, psychological, socio-cultural, and environmental causal factors in a naturalistically plausible way
Current Conceptual Models of Mental
Current Conceptual Models of Mental Disorder
Haslam (2002) begins his taxonomy with a category that captures those concepts in psychiatry that do not count as kinds, i.e., things that are completely continuous and are therefore non-kinds or continua. Such concepts are often referred to as dimensional. A good example of a non-kind is neuroticism. There is no non-arbitrary level of neuroticism at which someone counts as ‘neurotic’ or not, rather people can be more or less neurotic, with no clear ‘tipping point’ at which one can be labeled. Neuroticism therefore is a case of a pure continuum rather than a kind.
My use of ‘natural kind’ refers to a kind concept that picks out something real as opposed to conventional, selecting out a class of things which share properties to the degree that labeling them can be useful for our scientific purposes
natural kinds have a clear common causal structure; a single ‘latent variable’, or ‘essence’ underlying them. From philosophy, the classic example of natural kinds in this strict sense are atomic elements which are clearly defined by the number of protons present, for example, gold always has seventy-nine protons while helium always has two