The biopsychosocial model views disease and illness from a broader perspective than simply looking at the biology of the disease itself. It teaches us that when we see patients we are assessing and treating whole people, not just body parts. The impact of a disease has profound effects that reach all aspects of that individual, not just physically but psychologically and socially as well. Disease does not only affect that person and the different aspects of their own life, but the lives of those immediately around them as well. It also permeates through humanity as a whole so that, just as with individual trees in a forest, it is perhaps helpful for us to view the 8 billion humans on this planet as one large super-organism.

Covid-19 is a perfect example of how we should view all public health issues, not just viruses like the one that is affecting the world at the moment.  Right away, some definitions are going to be useful; the term disease refers to the actual biological process or pathology involved in a medical condition; in this case the virus.  Using scans and blood tests, for example, we can look for ‘biomarkers’ of disease to see if patients are affected.  The distinction between disease, and the illness that a disease may create, is an important one.  Illness is the outward expression of a disease i.e. the signs, symptoms and altered behaviours that result from changes to that person’s ‘normal’ physiology.  Symptoms, and the altered behaviours that they help to create, are unique to each individual.  It is quite common for someone to have a disease but no obvious symptoms at all.  For example someone might die of old age with no outward signs of dementia but on autopsy have the same visible brain disease as someone with Alzheimer’s.  Similarly, the vast majority of adults without any back pain have the same degenerative disc ‘disease’ seen on MRI as people of the same age who do suffer from back pain.  In the same way, we are now hearing that many people who have had covid-19 did not even realise they had it at all because the disease did not create any illness in those individuals.

When present, symptoms of a viral infection may be physiological (the ‘bio’ part of biopsychosocial model) such as a high temperature, shortness of breath or even tissue hypoxia and organ failure but, as we can see clearly with covid-19, there is also a considerable psychological and social impact that we must consider in order to fully understand these patients’ problems.  Only when viewed from this broader perspective are we able to provide the help that patients, their carers and their families require for meaningful long term health benefits. 

The biological, psychological and social variables will each change over time and take on different levels of significance as a disease progresses.  For example, someone who has only just contracted covid-19 might be quite anxious at the first signs of a persistent cough but may otherwise not feel at all unwell.  It may progress to the point where that patient has physiological signs that are serious enough to be sedated in ICU, at which point the worries of not being at work and how the mortgage will get paid are no longer at the forefront of their mind.  Attentions are turned to the more immediate life-threatening biological crisis going on in their bodies’ organs as the disease takes hold.  However, assuming that they recover, the illness may persist as the realisation that they have lost their job and are struggling financially hits home.  They might develop acute anxiety, no longer leave the house unless really necessary for fear of catching future coughs and colds.  Depression and a diminished sense self-worth are then more likely to develop and dietary, exercise and sleep habits inevitably begin to suffer.  Their body may be out of immediate danger from the virus but the impact of this acute episode can persist for a long time in ways that may be just as profound.

It is becoming clear that covid-19 is disproportionately affecting people from certain socioeconomic and ethnic backgrounds as well as with those with different religious and cultural attitudes towards healthcare.  Whilst some of the reasons for this may seem clear at first glance, how each individual reacts to a disease is as unique to that person as their finger prints, making it very difficult to see clear patterns.  It will be quite some task for epidemiologists to really understand the exact cause and effect relationships that exist with covid-19 in any given population.  We may never really understand its full complexity as it will not be possible to collect all potentially relevant demographic and lifestyle data from all affected patients.  Whilst many deaths will not be reported for various reasons, we should also remember that deaths that do get recorded are from those who have been found to have died with the disease but not necessarily from the disease.  Some estimates suggest that up to two thirds of deaths are in those who are at ‘end of life’ meaning that they were likely to have died anyway often from pre-existing comorbid disease.  As the current virus inevitably mutates, how do we retrospectively analyse data regarding infection rates and deaths from covid-19 with complete confidence?  The most valid method of estimating covid-19 deaths may well be to look at the average number of deaths in a given area in a ‘normal’ year and comparing it to the same period in the same area whilst covid-19 was pandemic.  This gives data on ‘excess’ deaths which we would then assume must be directly attributable to the virus.  Even this is not totally reliable.  For example, recent research has shown that the majority of people in the UK may be experiencing significant changes in sleep quality and this is quite likely to be attributed to underlying anxiety about the situation as a whole.  We already know that chronic anxiety has a profound effect on our immune systems and therefore our ability to fight disease.  We are more likely to be anxious if we are already in a poor socioeconomic group and have pre-existing and or compounding financial stresses or background health issues.  Could this be part of the explanation as to why people from poorer backgrounds are being disproportionally affected by this pandemic, just as it does with most public health problems?

Protracted pandemics will prolong anxiety and have quite significant psychological effects on survivors, healthcare workers, carers as well as those who were indirectly affected for a long time to come.  Without a cure in sight for months or even years, the anxiety felt by many people is not going to go away any time soon.  Despite the increased use of telemedicine, it is also increasingly hard to find services that provide non-pharmacological help.  Drug therapy may be the way that many people with anxiety or depression can ease their symptoms in the short term, but this is not ideal as it does not address the real underlying issues and comes with considerable side effects for many patients.  As well as fear of getting the virus and how one might be able to cope with it, many people are increasingly concerned about other aspects of their health, the ability to meet financial commitments now as well as the impact that this may also have on pensions and future financial stability.  There has been distress regarding getting enough food and other supplies as well as the psychological harm that social isolation does to people who are perhaps already vulnerable and need to keep distanced from people for the foreseeable future.  The countries that appear to have been most widely affected by this pandemic are, on the whole, developed and economically successful societies often with densely populated, urbanised areas.  Interestingly, these are also the countries that tend to have higher levels of mental health problems in the first place.

Whilst some people are easily able to get out to do their daily exercise, something that is vital for continued mental and physical well being, others do not have the luxury of nice parks and countryside on their doorstep.  Once outside a cramped urban flat, for example, many will find themselves in the crowds of other people that they supposed to be socially distancing from.  As with many things in society, some people are more inclined that others to follow the rules or simply more able to observe the rules for whatever reason.  Observing perceived behaviours in others who seem not to care in the way that you do can create frustration, even anger.  We have not seen significant social unrest as a direct consequence of covid-19 yet but this may be inevitable to some degree.  Sadly, frustration within households is also likely to see a rise in domestic violence as well as an increased prevalence of self-harm and suicidality.

The psychological impact is also not limited to infected patients who end up experiencing symptoms.  Healthcare workers are under increasing levels of stress and we are seeing many people working in front line jobs, especially those involved in caring directly for ill patients, suffering from emotional distress and post-traumatic stress disorder (PTSD).  This is something that is likely to continue long after the pandemic has gone away as the painful memories remain fresh in the minds of those people.  Healthcare workers are also describing feelings of worry about being carriers of the disease and guilt at the thought of spreading it to others.  There is the very real concern too about the increased risk of infection they carry and how they themselves might cope should they become symptomatic.

As Darwin pointed out, it is not necessarily the strongest that survive but the most adaptable.  Societies certainly need to review how they deliver healthcare now more than ever, but there is also a need for us as individuals to assume responsibility and review our own lifestyles and behaviours.  Public health crises highlight the fact that those who are already ill are invariably going to suffer more that those who are not.  An important point to make here is that ‘not being ill’ is not the same thing as ‘being in good health’.  We are seeing that those with higher blood pressure, higher BMI and other markers of metabolic and cardiovascular disease may well be at greater risk of dying from covid-19 even if they have not passed certain thresholds and become labelled as having health problems.  In the past, being advised to become healthier so that, perhaps decades from now, it may add a couple of years to your life expectancy may well have fallen on deaf ears.  However, realising that you may have ‘got away with it’ this time could well be more of a stimulus for us to lead healthier lives right now knowing that more of the same (or something similar) is likely to be just around the corner.  Eating smaller amounts of better quality food, losing weight, exercising more, managing stress and work life balance as well as ensuring good sleep quality are strongly associated with a healthier immune system.  Perhaps we should use this as a wake up call and really start to look after ourselves better.  Companies and organisations will play a big part in this; many sectors will reflect and realise that we were actually pretty productive working from home and, in the process, employees saved considerable amounts of money on travel and potentially on child care effectively giving them a ‘pay rise’ that cost employers nothing.  In another ‘win-win’, we have been able to significantly cut levels of pollution, including greenhouse gases almost overnight.  People are travelling less, more of us are consuming less and relying on locally manufactured goods and locally farmed foods.  Again, we would be wise to seize the moment; unless we continue to make massive efforts in this direction, the effects of climate change will make this current pandemic appear trivial in comparison.