The biopsychosocial model

When I first learnt about the biomedical model and the biopsychosocial model at university, in my head I was thinking of a sort of protocol, to apply to patients, that was somehow replacing the previous one. It looked to me like something extremely theoretical that I would never thought could be so important and present in my clinical practice every day.

Biomedical and biopsychosocial model

When we talk about these models we are therefore not referring to something tangible but to a way of thinking and interpreting reality.

The biomedical model has rather ancient origins: it developed around the sixteenth century, receiving the influence of the Catholic Church and the minds of the time, among which Descartes, Galileo and Newton stand out. Their theories and “modus operandi” are well recognizable within this model and we can identify two supporting pillars, two key concepts on which this way of understanding the human being, and his health, is based.

First of all, the biomedical model refers to reductionism: any complex phenomenon can be broken down into minor and simpler problems that can be always explained by molecular biology and chemistry. Tracing this principle back to medicine, a disease is any deviation from the normal condition and can be attributable to known or unknown natural causes. Any anomaly manifests itself with symptoms which in turn have the purpose of informing us of the presence of something that is not working properly inside our body and, finally, the elimination of the cause or anomaly always involves the recovery of the subject from pathology. It is evident how the person and their experience lose importance, while the problem and its anatomical cause become the real protagonists of this model.

Reductionism was the basis of the scientific method of the time, used by Galileo and Newton, which was based on the assumption that, once the resolved parts were put back together, the whole could be fully understood.

The second principle, on which the biomedical model is based, is the body-mind dualism supported by the Church and theorized by Descartes. Under the influence of Christianity, the body was seen as a weak and imperfect container of the soul, a machine whose failure could be identified and repaired. There is therefore the belief that mind and body are two distinct things and it should therefore not surprise us that permission was granted to study human anatomy on cadaver with the prohibition to analyze the brain and human behavior, which it was considered a religious rather than a scientific matter.

In this historical context, Descartes published his book ‘De Homine‘ reaffirming this distinction and starting to introduce the concept of pain with a drawing that has become very popular. In the picture below, pain is in fact represented as an informer, a stimulus that rises from the periphery to the body to warn the mind of the presence of a danger.

De Homine: Symbol of  the Cartesian model of pain

 

The problem with the biomedical model is that it quickly became part of popular belief, the limitations were set aside, and it became a dogma.

The scientific model predicts that a theory should be abandoned when it fails to adequately and convincingly explain all the data collected. This did not happen for the biomedical model as the facts that could not be explained were forced or even excluded. This leads to tracing any existing pathology to an alteration of any physiological mechanism and, in the event that one does not exist, not to consider it as a pathology.

The science of psychiatry therefore enters into crise: there are those who say that behavioral disorders are among the pathologies, as there must be some anomaly in the brain, while others argue that it should even be excluded from medicine since the disorders cannot be categorized as such.

Long story short, if on the one hand this model has brought advantages such as the systematic study of the human body and the formulation of diagnoses based on the collected data, on the other hand reductionism and exclusionism have led to a distorted and simplistic image of human being and health (1, 2).

The biopsychosocial approach

As we have seen so far, there are many inconsistencies and cases which cannot be explained by the biomedical model alone. For example, there are some clinical cases in which abnormalities are present but the patient does not show symptoms (3) or, conversely, the pain is very intense even in the absence of tissue damage.

It seems absurd but it really often happens that you meet patients who believe they have pathological asymmetries, muscle chains that ‘work poorly’ and vertebrae that need to be realigned in complete absence of symptoms! Or, again, many patients who wander from one professional to another to find a solution to their problem but who cannot find peace because imaging shows nothing to be fixed!

This suggests that the biological component is only one of the many factors that can lead to the onset of symptoms and certainly not the only one!

In 1977, George Engel published for the first time in Science (1) an article that highlights the need for a new model that puts the person and his bio-psycho-social context at the center. The biological part is however recognized as important but, alone, it is not able to justify the variety of possible clinical presentations. It is therefore also necessary to take into account the context in which the patient finds himself, his beliefs and expectations and the influence of the surrounding society.

This new model recognizes that reality is something complex and, if on the one hand, simplifying it is useful to be able to study and analyze it, on the other we must remember that in order to understand each subject and his unique experience we must necessarily have a global vision and a multifactorial approach!

Practical applications of the biopsychosocial model

The great revolution carried out by the biopsychosocial model is to shift attention from the symptom or structural alteration to the person. But what does this mean in clinical practice?

First of all, it means recognizing that each patient is an “expert in themself” and that in order to help him, it is not enough to read a report or make a precise assessment. Let us remember that pain, the reason why patients often come to us, is an unpleasant experience (IASP; 4) and, as such, cannot be measured objectively. And who better than our patient can describe their painful experience to us?

Another necessary consideration concerns imaging and laboratory tests. Both are an invaluable resource at our disposal but must be used wisely. They are very useful, for example, to exclude pathologies that are not within our competence, if we suspect them, but this does not mean screening all patients who come to our attention to have our backs covered. Finding asymptomatic structural anomalies is frequent, we know it well, however, the patient is not always aware of them and could misinterpret these findings and significantly increase the burden of anxieties and concerns regarding their health.

Giving importance to the person means making them an active part of their rehabilitation process. From a purely biomedical point of view, the clinician plays the fundamental role of the ” healer ” who identifies the malfunctioning part and resolves it without giving the patient a say. From this perspective, the therapy targets tissue and is often standardized with respect to the pathology. Paradoxically, subjects with similar ‘dysfunctions’ receive similar treatments regardless of the job, context, goals to be achieved or current concerns.

I believe that any therapeutic modality, even when supported by solid scientific evidence, if used in the wrong way, and out of context, can become inadequate for our patients.

Let’s take for example exercise, the strategy that today offers the best results for various problems: if we administered, for example, the same exercise protocol proposed in the literature to all patients with back pain, to strengthen the muscles deemed weak, we would not be doing nothing but trying to solve a structural problem, even if with a strategy supported by scientific evidence, in full biomedical style. Probably some patients will improve while someone else will not obtain satisfactory results regardless of the increase in the strength parameter.

Putting the patient at the center means making every therapeutic path absolutely personalized and unique, based on the indications found in the literature and adapting them to the patient’s needs and to our clinical experience. This means putting aside our pride and recognizing that there is no miraculous technique for back pain but that the patient’s recovery largely depends on themself, the context and, to a lesser extent, our skills and treatment plan.  This does not mean that our role is marginal, on the contrary, we have the task of guiding and educating the patient in this process or, at least, of not being part of all those factors that, instead, unnecessarily increase his apprehension and that condition, in a negative, way the outcomes.

The bio-psycho-social model in clinical practice is this and much more. Over the years, due to its complexity, it has been subject to adaptations and, if you like, simplifications that alter its original meaning.

Many have applied this model to aspects of the clinic, such as pain. According to this variant, the pain would depend on the set of biological, psychological and social factors and, vice versa, these factors would influence the painful experience. While this way of understanding pain can facilitate us in comprehending the factors at play, on the other hand it is certainly a reductionist vision of such a complex and personal experience! Furthermore, once again, it would be the symptom and not the person at the center of attention (6).

Others have tried to use the bio-psycho-social model to identify which of the 3 areas could be the most affected to make it the main object of treatment or, again, they have eliminated the biological and anatomical part in favor of the other two. These adaptations are clearly reductive with respect to the original complexity of the biopsychosocial model and it is in no way possible to separate the 3 areas or leave out one but, on the contrary, all must be seen as an integral part of the person and the environment in which they live (7) .

Conclusion

We can therefore conclude by saying that the biopsychosocial model is undoubtedly more complex, however, thinking and acting according to the biomedical model can be extremely reductive and not adequate for understanding the actual complexity of the person in front of us.

Translated from “Il modello biopsicosociale” written by Nicole Schenato, PT, BSc, OMPT

References:

1. Engel GL. The need for a new medical model: a challenge for biomedicine. Science. 1977;196(4286):129-36.
2. Engel GL. The clinical application of the biopsychosocial model. Am J Psychiatry. 1980;137(5):535-44.
3. Brinjikji W, Luetmer PH, Comstock B, et al. Systematic literature review of imaging features of spinal degeneration in asymptomatic populations. AJNR Am J Neuroradiol. 2015;36(4):811-6.
4. https://www.iasp-pain.org/Education/Content.aspx?ItemNumber=1698
5. Fillingim RB. Individual differences in pain: understanding the mosaic that makes pain personal. Pain. 2017;158 Suppl 1:S11-S18.
6. Stilwell P. An enactive approach to pain: beyond the biopsychosocial model. Phenomenology and the Cognitive Sciences, 2019.
7. https://cor-kinetic.com/have-we-ballsed-up-the-biopsychosocial-model/