I’ve had an interest in clinical psychology for some time, having studied abnormal psychology during A-level. I’m particularly interested in the definition of mental illness and how it is perceived by both the profession and the public. I guess my interest is primarily philosophical: does mental illness really exist? How is it to be differentiated from “normal” suffering? Can it legitimately be compared to other kinds of (much better understood) illness, such as influenza and cholera?
Mental illness ≠ “regular” illness
Long ago I came to the conclusion that mental illness could not exist in the way that influenza or cholera can. Firstly, both these illnesses can be demonstrated to have a specific cause (viral, bacterial) and their mechanisms of action are fully understood. Patients may display different symptoms, but a group of similar symptoms exist for every person who has the illness. Mental illness cannot be traced back to a specific identifiable source, their underlying neural mechanisms are not understood and symptoms may vary wildly between individuals with the same mental illness. Rarely does a patient display symptoms that make them a perfect fit for a diagnostic category. Major depression, for example, is rarely displayed as just major depression – often various anxieties, phobias, or other disorders such as obsessive-compulsive disorder and post-traumatic stress disorder are also diagnosed.
Is the problem just that clinical psychology is too young?
An obvious response to this would be to argue that this difficulty in ease of diagnosis stems from how young (modern) clinical psychology is as a science; given more research and time diagnostic categories will better fit actual human suffering. Looking at the history of clinical psychology, however, leads me to believe that this is not the case. Definitions of disorders change wildly over time to meet current social trends (the declassification of homosexuality as a disorder in 1973 is a great example of this), and pharmaceutical companies have a disturbing influence on the prevalence of certain disorders (the huge recent increase in diagnoses of depression is without a doubt fuelled by the companies who manufacture SSRIs, especially fluoxetine).
I am not alone in this worry. In fact, James Scully (medical director of the American Psychological Association, the group who produce the Diagnostic and Statistical Manual of Mental Disorders, otherwise known as the DSM) puts it: “The DSM will always be provisional; that’s the best we can do.” APA research chief Darrel Regier says, “The DSM is not biblical. It’s not on stone tablets.” Gary Greenberg (in his recent article “Inside the Battle to Define Mental Illness”, http://www.wired.com/magazine/2010/12/ff_dsmv/all/1) states:
The real problem is that insurers, juries, and (yes) patients aren’t ready to accept this fact. Nor are psychiatrists ready to lose the authority they derive from seeming to possess scientific certainty about the diseases they treat. After all, the DSM didn’t save the profession, and become a best seller in the bargain, by claiming to be only provisional.
Greenberg also says that:
for patients to accept a diagnosis, they must believe that doctors know—in the same way that physicists know about gravity or biologists about mitosis—that their disease exists and that they have it. But this kind of certainty has eluded psychiatry, and every fight over nomenclature threatens to undermine the legitimacy of the profession by revealing its dirty secret: that for all their confident pronouncements, psychiatrists can’t rigorously differentiate illness from everyday suffering. This is why, as one psychiatrist wrote after the APA voted homosexuality out of the DSM, ‘there is a terrible sense of shame among psychiatrists, always wanting to show that our diagnoses are as good as the scientific ones used in real medicine.’
Mental “illness” is not the binary opposite of mental “normality”
Rather that stemming from the youth of the profession or the difficulties stemming from corruption by pharmaceutical companies, I think the problem of adequately defining diagnostic criteria for mental illness comes from a fundamental flaw in the concept itself. Basically I find the concept of mental “illness” as the binary opposite of mental “normality” to be rather suspect. There seems to be no simple point where a person becomes mentally “ill” after previously being mentally “normal”. Clinical psychology ignores this issue altogether, preferring to stick to the idea that if you have several of a group of symptoms for a disorder, then you have that disorder. Greenberg states:
descriptive psychiatry also has a major problem: Its diagnoses are nothing more than groupings of symptoms. If, during a two-week period, you have five of the nine symptoms of depression listed in the DSM, then you have “major depression,” no matter your circumstances or your own perception of your troubles.
It is likely, however, that you would have had perhaps one or two of the symptoms for some time and during other times in your life may have been quite sad, possibly on the cusp of a diagnosis, but never quite matched the amount of symptoms needed for one.
Labelling these cognitive idiosyncrasies as “illnesses” or “disorders” is likely what has lead to patients needing their doctors to be as certain with their diagnoses as they would be had the patient had influenza or cholera. The general public believes that mental illness is analogous to physical illness. Unfortunately this is the not the case and never has been. It seems to me that a more accurate way of looking at mental “illness” would be to see such “illnesses” as manifestations of extreme versions of certain cognitive styles.
Central coherence and autism
For example, one of the major obstacles to autism research has been identifying exactly what the main cognitive deficit is. One recent account (Happé, 1999) argues that individuals with autism have weak “central coherence”. Central coherence is a wide-ranging cognitive ability whereby individuals are able to filter out information deemed unnecessary to the task at hand. This can be perceptual, verbal and visuospatial. People who have normal levels of central coherence can pick out contextual meanings of metaphorical constructions in social language, remember the “gist” of a story rather than every last detail, and focus on aspects of a highly cluttered visual field that are relevant to the practical demands of their current situation (such as navigating through the middle of a busy city centre). Autistic individuals, however, are more likely to focus on the literal meanings of metaphorical constructions in language, remember the entirety of a story verbatim, and attend to all aspects of a cluttered visual field, thus suffering from perceptual overload.
Interestingly, however, autistic individuals can have savant abilities in certain areas, such as music and visual art. Furthermore, weak central coherence appears in the immediate families of autistic individuals. Fathers of children with autism are overrepresented in engineering professions and it appears that in their case weak central coherence is a benefit rather than a burden. For these reasons Happé claims that we should see weak central coherence as being a cognitive style rather than a cognitive deficit. For Happé, there might be a normal distribution of cognitive style from weak central coherence involving preferential processing of parts to strong central coherence involving preferential processing of wholes.
An extreme lack of central coherence will quite obviously be maladaptive and cause many social learning problems. A person with such a cognitive style will be unable to filter irrelevant social information from relevant information and is likely to suffer from perceptual overload through an inability to filter out irrelevant perceptual stimuli. Importantly, however, this is not a mental illness – it is just a style lying at the edge of a normal distribution curve of central coherence abilities.
Cognitive styles in other mental illnesses
It is likely that there are other things going on with the autistic individual. Weak central coherence may be just one of several issues. If it is the most substantially important of these, however, and it is just one kind of cognitive style that exists on a continuum, then it seems strange to label it a mental illness. Perhaps something similar is happening in other mental illnesses. Social anxiety disorder, for example, is characterised by chronic extreme sensitivity to negative social stimuli. It is possible that sensitivity to social stimuli is a cognitive trait that exists on a continuum – some are highly sensitive, some are less sensitive. Ketay et al. (2007) argue that highly sensitive people comprise about a fifth of the population and process social information more deeply and thoroughly than most people. Belsky and Pluess (2009) show that individuals vary in their sensitivity to experiences or qualities of the environment they are exposed to. Some individuals are more sensitive to such influences than others; not just to negative but also to positive ones. There seems to be a basic difference in social sensitivity between individuals, which seems likely to exist on a continuum. Socially anxious people are more likely to attenuate to negative social stimuli, however, separating them from highly socially sensitive people who do not focus on negative stimuli. It seems likely, however, that a socially sensitive temperament coupled with a higher degree of negativity bias (which is in itself a basic human cognitive heuristic) could, over time, lead to increased levels of social anxiety.
Furthermore, social anxiety (not social anxiety disorder) is actually highly prevalent. Most children are socially anxious at times, especially when meeting new people. Most adults get socially anxious at times around people to who they are attracted, or just before giving a speech, for example. Wakefield et al. (2004) argue that many people labelled as having social anxiety disorder are just temperamentally high in social anxiety rather than suffering from a disorder per se.
Fundamentally, it seems that labels such as “depression”, “anxiety” etc. are merely useful fictions, created initially to help those who desperately need help but with little relation to psychological reality. Undoubtedly, diagnosis and treatment of mental illness helps many people. Unfortunately, diagnoses and treatment also harms many people, perhaps because of the inaccuracies inherent in the very concept of mental illness itself. They may be many things: cognitive styles, temperaments, etc., but they are not illnesses.
Belsky, J., & Pluess, M. (2009). “Beyond Diathesis-Stress: Differential Susceptibility to Environmental Influences”. Psychological Bulletin, 135(6), 885-908.
Greenberg, G. (2010) “Inside the Battle to Define Mental Illness”, Wired magazine, December 2010: http://www.wired.com/magazine/2010/12/ff_dsmv/all/1
Happé, F. (1999) “Autism: cognitive deficit or cognitive style?” in Trends in Cognitive Sciences, Vol. 3, No. 6, p. 216-222
Ketay, S., Hedden, T., Aron, A., Aron, E., Markus, H., & Gabrieli, G. (2007). The personality/temperament trait of high sensitivity: fMRI evidence for independence of cultural context in attentional processing. Poster presented at the annual meeting of the Society for Personality and Social Psychology, Memphis, TN. Summary by Aron (2006): “A functional study comparing brain activation in Asians recently arrived in the United States to European-Americans found that in the nonsensitive, different areas were activated according to culture during a difficult discrimination task known to be affected by culture, but culture had no impact on the activated areas for highly sensitive subjects, as if they were able to view the stimuli without cultural influence.”
Wakefield, J.C., Horwitz, A.V., Schmitz, M.F. (2004) Are We Overpathologizing the Socially Anxious? Social Phobia From a Harmful Dysfunction Perspective. Can J Psychiatry 49:736-742.