Why "Biopsychosocial" Both Begins and Ends With "Bio"

Biomedical and biopsychosocial frameworks for understanding health and disease are often seen as mutually incompatible: The biomedical model, focusing on disease as an exclusively biological phenomenon, and its successor, placing the body within psychological and sociocultural contexts.

This view is accurate but oversimplified. It overlooks core aspects of the Biopsychosocial model that ground its "Psychosocial" components in biology. Knowledge of this grounding was shared with us by biological scientists and physicians well before the field of Health Psychology emerged.

Biology does not come into the picture only at the moment that psychosocial factors initiate a disease process. Bio-psycho-social interplay is programmed into the human genome and activated by environmental factors that define the human condition. Biomedical and psychosocial parts of the equation are both necessary, but neither is sufficient, for a comprehensive understanding of health and disease.

This can be illustrated by the many ways that biological and psychosocial processes participate in the development of physical health problems as a consequence of their functional interdependence before those problems arise. Here are just a few examples that involve coordinated biological and behavioral activity in stress-related disease.

Stress Biology and Behavior

Walter Cannon and Hans Selye, both biological scientists, identified physiological mechanisms that provide the foundations for understanding how psychological stress can promote physical disease. A clear example of an evolutionary adaptation, Cannon’s biological fight-or-flight response has a behavioral basis: It consists of endocrine, autonomic, and cardiovascular activity that supplies fuel, in the form of oxygenated blood, which supports the vigorous, large-muscle activity required to survive emergencies.

Selye’s General Adaptation Syndrome (GAS) highlights endocrine activity, evoked by noxious physical and emotional stimuli that he referred to as stressors, through which energy stored as glucose is mobilized. This popularized the term “stress” and encouraged many researchers, including psychologists, to conduct stress research. Selye called attention to the possibility that wear-and-tear caused by repeated activation of the GAS may promote disease, and its effects on the thymus hinted at the impact of stress on the immune system.

These discoveries uncovered biobehavioral phenomena in which behavioral and physiological activity form a single system. Each is part of a survival mechanism in which bodily activity functions to support action in response to the perception of potential harm. This mind-body connection is built into our genome.

Behavioral Adjustment to Environmental Stressors

In the earliest observations of instances of disease and death following the occurrence of major life events, sympathetic and parasympathetic branches of the autonomic nervous system, which regulate energy storage and mobilization, were invoked as explanatory mechanisms. According to some accounts, whether the event was positive or negative in valence was less important than the degree to which it required effortful life adjustments. Similarly, researchers have focused on the demand for effortful activity, or effort-reward imbalance, as the feature of stressful occupations that accounts for their impact on physical disease. Current views have more elaborate explanatory models and point to additional features of the precipitating life events and conditions. But the influence of Cannon's and Selye's contributions remains clear.

Source: Andrea Piacquadio/Pexels

Emotional Traits and Conditions

Associations linking personality and disease can be traced back to the writing of Hippocrates and Galen. They discussed the role of emotional temperaments in physical disease: Melancholic (depressive), Sanguine (optimistic), Choleric (irritable), and Phlegmatic (inexpressive).

The basis for each of these associations was a bodily humor (fluid): black bile, blood, yellow bile, and phlegm, respectively. Although their biology was flawed, Hippocrates and Galen provided a reasonably accurate description of individual differences in emotionality. Moreover, their ideas foreshadowed current interest in the physical health effects of depression, optimism-pessimism, trait anger and hostility, and emotional expression.

Stress Essential Reads

Ready. Aim. Fire: Mitochondria as Treatment Targets

Gut-Brain Treatment Goes Viral

Although their interests and contributions extended well beyond medical practice, both Hippocrates and Galen were physicians. There followed a long line of physicians whose ideas also were prescient as regards the role of personality and physical disease. Notable examples include 18th-century physician John Hunter, who some believe predicted his own, anger-induced death due to heart disease, and Sir William Osler, often described as one of the founders of modern medicine, who pointed to a driven, pressured approach to life as a factor in heart disease.

Observations such as those were crystalized in the work of Ray Rosenman and Meyer Friedman, cardiologists who conceptualized the Type-A behavior pattern and generated evidence regarding its association with coronary heart disease and possible explanatory mechanisms. Although the current view paints a more complex picture, their work ushered in an era in which emotional traits and conditions, including anger and hostility, depression, anxiety, and trait neuroticism are viewed as likely playing a role in enhancing coronary risk.

In addition to promoting cardiovascular disease, emotional traits and conditions are also seen as precursors to other physical health problems. The plausibility of hypotheses regarding their effects on health rest squarely on Cannon and Selye's discoveries. Accounts of the relevant explanatory mechanisms start by describing the neuroendocrine systems now understood as the basis for Fight-or-Flight and the GAS.

Pathways to Disease

Research building on the work of Cannon and Selye draws direct connections linking the behavioral functions of stress biology and the development of disease. The reactivity hypothesis holds that cardiovascular and metabolic changes associated with active efforts to cope with psychological stressors initiate heart and blood vessel disorders. Ecological accounts of how stress may promote infectious diseases and cancers assign a key role to the energy costs of adaptation to stressors. Health outcomes may depend on how energy requirements of mobilization, suppression, and dysregulation of the immune system balance against those of behavioral activation and deactivation.

Source: Elīna Arāja/Pexels

If stress-related disease can be traced to coordinated activity of biological and behavioral systems that are activated by stress, what of other forms of bio/behavioral co-regulation? Examples can be found in recent analyses of associations linking mental and physical health problems.

In one, rather than viewing post-traumatic stress disorder (PTSD) as a separate syndrome that increases risk of cardiovascular disease (CVD), it is argued that both PTSD and CVD are part of the same systemic disorder. In another, it is proposed that comorbid mental and physical disorders reflect dysregulation of brain systems responsible for both somatic and higher-level cognitive activity and their interplay.

Both of these hypotheses reflect a perspective in which biological and psychosocial processes are inherently and intrinsically interactive. Not only are the mind and body well-acquainted, they are wedded to each other. Both in sickness and in health.

Copyright 2023 Richard J. Contrada.