normal distribution

 

In his writings on the topic of diagnosis, the French philosopher and physician Georges Canguilhem makes a crucial distinction between pathology and abnormality, thus paving the way for the studies of his student Michel Foucault on the topics of psychiatric power and biopolitics. In Canguilhem’s view, decision making about normality and abnormality is generally based on two factors. One starts from the observation that there is variability in the ways human beings function: individuals present with a variety of behaviours just as their mental life is characterized by a variety of beliefs and experiences, of which some are more prevalent than others. Then, a judgment is made about (ab-)normality; this tends to be based on a norm or standard against which all behaviours are evaluated and considered as deviant or not.

At this level, two possibilities open: a judgement is made based on either psychosocial criteria or statistical norms.

If the judgement is based on psychosocial criteria, it is the extent to which the individual’s functioning fits his environment that is assessed. Following this logic, behaviours are ‘normal’ if no-one is particularly concerned about it or if they don’t cause the others inconvenience. This line of reasoning might seem plausible, but it is based on the idea that individuals must adapt to their context: “To define abnormality in terms of social maladaptation is more or less to accept the idea that the individual must subscribe to the fact of such a society, hence must accommodate himself to it as to a reality which is at the same time a good”. As social conventions change across time, identical modes of human functioning will be judged differently. The case of homosexuality illustrates this well: in the early 20th century it was mainly seen as a moral aberration; and in the works of early sexologists homosexuality was classified as a perversion. This gave rise to the medicalized idea of homosexuality as a mental disorder. However, following much protest in the 1970s, homosexuality was gradually accepted as a sexual preference, alongside heterosexuality.

Applied to the DSM-5 it can be concluded that some disorders, particularly those diagnosed in children, remain strongly based on judgement in lieu of norms that are imposed onto the individual. For example, the criteria for diagnosing ADHD exclusively build on third party opinions about the individual and use common sense ideas about desired behaviours in specific contexts (e.g. school) as the standard against which behaviours are evaluated. Indeed, diagnostic criteria for ADHD include characteristics like “Often does not seem to listen when spoken to directly (e.g., mind seems elsewhere, even in the absence of any obvious distraction),” “Is often forgetful in daily activities (e.g., doing chores, running errands; for older adolescents and adults, returning calls, paying bills, keeping appointments)” and “Often has difficulty waiting his or her turn (e.g., while waiting in line)”. In the DSM-5, and other relevant literature, these diagnostic criteria are rarely discussed, leaving all interpretation as to a) what is meant by the term ‘often,’ and b) why specific behaviours are deemed problematic, down to the judging diagnostician. Thus, it is the professional’s personal opinion that functions as the norm against which an individual is evaluated. In other words, because strict scientific standards for making such evaluations do not exist, it is the belief system of the diagnostician that determines the standard. This can provoke over-diagnosis [6], especially if particular professionals are inclined to problematize particular behaviours.

The other option for evaluating the (ab-)normality of human mental functioning is to refer to statistical norms. Canguilhem indicates that this kind of judgement is rooted in the work of the Belgian mathematician Adolphe Quetelet (1796-1874), who aimed to study human functioning through a new discipline he coined ‘social physics.’ His underlying thesis was that social scientists should study the variability of human characteristics, ranging from physical qualities to aspects of psychological and behavioural functioning. Quetelet aimed to map how people generally function, thus giving rise to a mode of thinking ‘in which normality’ is considered in terms of the statistical normal distribution. In this line of reasoning normality implies a mode of functioning that closely adheres to the mean or median in statistical distribution. Abnormality, in its turn, implies a mode of functioning that strongly deviates from the average: individuals with an extreme score in terms of the normal distribution are abnormal. From a Foucauldian point of view, this statistically-based evaluation of human behaviour engenders a bio-political approach to human functioning: based on a marked deviance from the average, individuals are subjected to disciplinary practices that aim to engender (self-)control.

Nowadays, certain psychological testing practices function according to the same logic: an individual’s score is compared to cut-off values that are listed in so-called norm tables. Such tables are composed of scores obtained by administering the same test in large populations (clinical and/or non-clinical). To evaluate the individual’s test score, professionals often only compare it to the distribution of scores in the general population, and thus determine whether it deviates from the norm or not. According to Nikolas Rose psychological tests provide “a mechanism for rendering subjectivity into thought as a calculable force.” In his view psychological assessment and evaluation practices provide a technology, starting from which contemporary man inspects and perfects himself, and likewise scrutinizes and manages others. Through the lens of psychological testing, we began to think of ourselves as manageable machinery. Assessment instruments map individual differences, appraise them in terms of statistical or other social norms, and engender “techniques for the disciplining of human difference” .

Canguilhem argues that in the diagnosis of pathology, by contrast, the subjective experience of human suffering is the hallmark. Indeed, for diagnosing pathology, one cannot start from societal or statistical norms. “Pathological implies pathos, the direct and concrete feeling of suffering and impotence, the feeling of life gone wrong”. Such a diagnosis of pathology does not build on the opinions of experts, but on patients’ appraisal of their own distress. Moreover, it does not neglect the heteronomy in the patient’s functioning [22], but examines how heteronomy is experienced.

By referring to the experience of distress in the definition of mental disorders, the DSM-5 takes into account pathology. Yet as one examines specific DSM-5 disorder criteria one sees that for certain conditions the subjective experience of distress is not necessarily crucial. For example, none of the diagnostic criteria for ADHD refers to the experience of distress by the child or adult for whom the diagnosis is considered . In the diagnosis of other conditions, like Major Depressive Disorder, the subjective experience of distress is taken into account more strongly. In our view, the quality of psychiatric diagnosis would be greatly enhanced if pathos, as mentioned by Canguilhem, were mandatory to all diagnostic decision making.

Excerpt from the paper: Vanheule, S. & Devisch, I. (in press). Mental suffering and the DSM-5: a critical review. The Journal of Evaluation of Clinical Practice. http://onlinelibrary.wiley.com/doi/10.1111/jep.12163/abstract.

Full paper available upon request.

 

Stijn Vanheule

About Stijn Vanheule

Stijn Vanheule, Ph.D., is a clinical psychologist, associate professor at Ghent University (Belgium), and psychoanalyst in private practice (member New Lacanian School for Psychoanalysis). He is the author of the books The Subject of Psychosis: A Lacanian Perspective (2011) and Diagnosis and the DSM: A critical Review (2014), and of multiple papers on Lacanian and Freudian psychoanalysis, psychoanalytic research into psychopathology, and clinical diagnosis.