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In 1977, George Engel famously argued that medicine in general and psychiatry in particular ought to shift from a biomedical perspective of disease to a biopsychosocial (BPS) perspective on health. He argued that the biomedical perspective was too reductionistic and that a holistic perspective grounded in general systems theory was necessary to address health-related issues. The World Health Organization seems to agree with Engel's view in that it defines its central mission as improving well-being which is defined as an overall state of health and happiness at the biological, psychological and social levels.
To get a flavor of the difference in emphasis between a biomedical and biopsychosocial view, consider the hypothetical case of Joe, an overweight 60-year-old man who rarely exercises. It is snowing and his younger, fitter brother is visiting for the week. Joe’s wife complains that he never shovels the snow and shoots a knowing glance to his brother. With his masculinity threatened, Joe grabs a shovel and begins to vigorously clear the driveway. Fifteen minutes later, he has a heart attack and dies. If you are wondering if this really does happen, it does—emergency rooms intentionally gear up for an increase in heart attacks following snowstorms.
Engel argued that the biomedical lens only focuses attention on the physiological mechanisms associated with the heart attack, which results in psychological and sociological factors being either systematically excluded or ineffectually reduced (i.e., conceptualized in physiological terms). Engel argued this was a big mistake and that to appreciate health in general we must consider the psychological, behavioral, and social dimensions that contribute to illness-related events. For example, in the case above, the man’s pride was threatened and he was either ignorant of or in denial about his vulnerability. In addition, his exercise and eating habits were centrally associated with physiological vulnerability to have a heart attack. And the social role of masculinity and even the broad ecological environmental factors (i.e., the snowstorm) provided the context for the action—all of which were directly related to his heart attack and subsequent death. The BPS model additionally allows for the consideration of such issues like the belief factors associated with healing (i.e., what bio-medicine refers to—or dismisses—as "placebo" effects) and general the social conceptions of disease and the socially constructed elements that justify policies and the behaviors of healers and patients.
The advantages of the BPS model are found in its holism, awareness of levels in nature, and inclusiveness of diverse perspectives. Its advocates argue for the necessity in thinking about and treating illness via a BPS lens by pointing out that social and behavioral factors play an obvious and major role in human health overall (e.g., poor eating habits and obesity, smoking, excessive drinking, risk-taking behavior, war, stress/anxiety/depression, and on and on), and a reductionistic physicalism does not help in our understanding of these phenomena.
Within the field of psychiatry in particular, the BPS model provided a broader home that allowed for at least some basic reconciliation between the two dominant conceptions psychiatrists have of mental illness, which are: 1) the biological psychiatry view that mental disorders arise from faulty biology and 2) the psychodynamic view that emphasizes the psychological dimensions of maladaptive patterns of thinking, feeling and acting and relating. By providing at least a general framework for these two perspectives, the BPS became the most frequently adopted perspective in psychiatry, although the biomedical view remains prominent.
In terms of other health professions (i.e., nurses, social workers, counselors, occupational therapists, and professional psychologists), the BPS model is the basic framework for understanding health and illness. Within psychology, some have argued that the biopsychosocial framework provides the central pathway to unify the field of professional psychology.
But not everyone agrees the BPS model represents an advance in medicine, and there are a number of different criticisms that can be effectively leveled against it. For starters, there are those who are philosophical physicalists who believe that biological, psychological and social levels of analysis are either epiphenomenal or can be fully reduced to the physical. Although I don’t find this philosophical position defensible, it does deserve mention, especially because so-called downward causation (i.e., higher levels of reality having causal power relative to lower levels) is philosophically tricky.
One of the most generally cited problems with the BPS model is that its inclusiveness results in an unscientific, “fluffy,” pluralistic approach where, in the words of the dodo bird in Alice in Wonderland, all perspectives have won and deserve prizes. The goal of science is analytic understanding and that understanding requires intelligible frames that break the world into its component parts. In contrast to this, the BPS model potentially justifies a morass of “anything goes” in medicine and health. S. Nassir Ghaemi has offered one of the most systematic critiques of the BPS model.
From the critics’ perspective, the potentially confusing and convoluted aspect of the BPS model becomes particularly clear when we try to define these terms and their boundaries and interrelationships. Consider, for example, the following questions: What is the relationship between biology and the physical and chemical processes that take place within the cell? Is biology just complicated chemistry? Or consider the question of, what, exactly, is the relationship between biology and psychology? That is, where does biology end and psychology begin? What about the relationship between psychology and behavior—are they the same thing or different? Moving up a level, where does psychology meet the social? Is a family of bonobos a psychological or a social level entity? What about a human family living in Canada? Moving further up the scale, what is the relationship between culture and society? Does the biosphere include the cultural or are they separate? Is the whole of the earth a singular organism-like creature or not? To put these questions another way, is the BPS perspective synonymous with and shorthand for the particle-atom-molecule-cell-organ-organism-animal-group-cultural-ecological view that nature comes in levels and we need to consider them all? Does this position pass for science or is it mush?
Another related criticism exists on the pragmatic side of things. By being all-inclusive, Ghaemi argues that the physician who adopts the BPS model is in real danger of losing clear boundaries regarding their knowledge and expertise. In short, must a physician now understand everything? It is reasonable and appropriate that medical doctors take into consideration the personality and sociological factors associated with health? Should graduate-level training in these areas be part of their curriculum? Medical doctors have so much to learn as is. If knowledge expectations and training become too diffuse, then expertise will inevitably suffer. It is worth noting here that the general trend in medicine has been toward specialization, not in broadening one’s perspective.
Here is a summary list of critiques of the BPS model from Ghaemi (2011).
I believe these critiques of the biopsychosocial model have relevance, especially the following: 1) whether the BPS frame is appropriate for medicine; and 2) the critique that the boundaries between the domains are not at all clear. In the next post, I explain why we should move from the ambiguous biopsychosocial model offered by Engel for medicine to the physical-bio-psycho-social view of nature for all the sciences afforded by the Tree of Knowledge System.
