Lecture 2
Learning session overview and objectives
The instructor emphasizes class structure on content days: small group activities, then regroup to discuss.
The day’s focus is to illustrate how lectures are structured, including what to expect from the class and the stated learning objectives.
Students are told there is no formal study guide; some students have found learning objectives on slides useful as a study guide, since they highlight major points the instructor wants students to grasp. The instructor notes that not everything will be tested, but the main pieces align with the day’s goals.
Outline of the session:
Begin with an outline and learning objectives; these objectives are also posted on Canvas.
Activities are pulled from slides so students can review ahead of time; some content in slides may be unavailable during activities (the model used).
Anecdote about the instructor getting lost on the way to class and experiencing a moment of “PTSD walking into the hallway” to humanize the lecture.
LI for today (Learning Items):
Start with the biomedical model and its two philosophical roots: mind–body dualism and reductionism.
Introduce the biopsychosocial model, its components, and its systems approach.
By the end, students should be able to:
name and differentiate between the biomedical and biopsychosocial models;
differentiate infectious disease from chronic disease and describe four reasons why chronic disease overtook infectious disease as leading causes of death in the US and other industrialized countries;
describe and provide examples of each factor of the biopsychosocial model; and
apply the biopsychosocial model to a diagnosis and treatment plan.
A Zoom attendance note: one student is joining remotely due to illness; the instructor will share slides with them.
The instructor announces a short vignette (Jessica) to anchor discussion about how illness is evaluated and treated.
The class discussion includes a prompt to generate questions or information you would ask if Jessica were a patient, highlighting the importance of gathering both biological and contextual (psychological/social) information.
The class data exercise: a 2–3 minute individual reflection, then pairs discuss potential causes of three leading chronic illnesses (heart disease, cancer, diabetes) to illustrate how multiple factors contribute beyond biology.
A demonstration that while genetics may be involved, most contributing factors discussed by students are behavioral/psychological and social, illustrating a shift beyond pure biology.
The instructor references George Engel (1977) and his critique of the biomedical model, arguing for the biopsychosocial model, which includes the patient’s experience in health and illness.
The three factors of the biopsychosocial model are introduced in parallel:
Biological factors: genetic predispositions, inherited conditions, structural abnormalities, age, sex, etc.; example given: BRCA2 mutation (BRCA2) associated with higher risk for breast/ovarian cancer, etc.
Psychological factors: cognition, emotions, motivation; personality traits (e.g., conscientiousness) and their links to health behaviors; impact of stigma; smoking as a health-behavior example.
Social factors: family, friends, community, and the physical environment; access to groceries vs. food deserts; societal values and their influence on behaviors (e.g., smoking, drinking).
The “systems approach” is contrasted with reductionism: complex health outcomes arise from interacting factors rather than a single cause.
A two-scenario example (John A vs John B) illustrates how identical genetic risk can lead to different outcomes depending on socioeconomic status, access to resources, stress, and lifestyle opportunities.
The class is invited to reflect on personal experiences with biomedical vs biopsychosocial approaches in medical encounters, and to consider how health care could be more patient-centered.
Jessica vignette revisit: after learning about biopsychosocial factors, students are asked to think about additional social/psychological questions to ask Jessica and discuss treatment options if cancer is diagnosed.
Sample student contributions cover social support, motivation to seek help, stress measurement, life/work context, access to nutritious foods, financial resources, and potential treatment options including referrals, imaging, biopsy, surgery, and radiotherapy or chemotherapy; also potential non-biomedical options like support groups and clinical trials.
The instructor wraps up with a plan to assess learning objectives via an in-class email exercise, where students reply with their understanding of:
differences between the models;
infectious vs. chronic disease and four reasons chronic disease overtook infectious disease as leading causes of death in the US; and
examples and descriptions of biopsychosocial factors; plus a reflection on the Jessica case.
The closing note emphasizes a shift from a biomedical to a biopsychosocial, patient-centered framework and invites careful engagement via the post-class email exercise.
Learning objectives for today
Name and differentiate between the two models of health: biomedical and biopsychosocial.
Differentiate infectious disease from chronic disease and describe four reasons why chronic disease overtook infectious disease as the leading cause of death in the US and other industrialized countries.
Describe and provide examples of each factor of the biopsychosocial model (biological, psychological, social).
Apply the biopsychosocial model to a diagnosis and treatment plan in an applied scenario (as done with Jessica during class).
The biomedical model: core concepts and context
The biomedical model is an approach to health that suggests disease and illness are rooted purely in biology; it is the dominant model in the medical system.
It focuses on biological factors and largely excludes psychological and social factors when explaining illness and guiding treatment.
Under this model, if you receive medical care for a physical illness, you are considered healthy only if biological abnormalities are addressed.
Rooted in two philosophical perspectives:
Mind–body dualism: the mind and body are separate entities; the mind is not considered to influence physical health in the medical view.
Reductionism: complex phenomena can be explained by one simple factor, namely biology.
Practical implication: the approach is especially strong for infectious diseases, where biology and pathogens are central to disease causation and treatment.
Philosophical roots in detail
Mind–body dualism (separation of mind and body):
If the mind and body are separate, the mind’s impact on physical health is minimal or nonexistent under that view.
Reductionism (explanation via a single factor):
Complex diseases are reduced to a single explanatory mechanism—biology.
Together, these roots shape a medical system that prioritizes biological explanations for illness and often overlooks psychosocial contributors.
Infectious vs chronic disease: definitions and examples
Infectious diseases:
Acute, sudden onset illnesses caused by pathogens (bacteria, viruses).
Examples: common cold, influenza, tuberculosis, HIV, COVID-19, measles.
Chronic diseases:
Long-lived, degenerative illnesses that worsen over time and persist.
Examples: cancer, heart disease, arthritis, stroke, asthma (note: asthma can be episodic but is often discussed in chronic terms).
Key distinction: infectious diseases are often addressed with vaccines, antibiotics/antivirals, and public health measures; chronic diseases reflect long-term risk factors and lifestyle interactions.
Four reasons chronic disease overtook infectious disease as leading causes of death
Prevention measures reduced infectious disease mortality:
Access to clean water, water treatment facilities, and sewage treatment reduces infection risk.
In many developing countries, lack of these infrastructures keeps infectious disease high.
Vaccines drastically reduced infectious disease burden:
Vaccines eradicated or drastically reduced diseases like polio and measles; occasional resurgences occur where vaccination rates drop.
Increased longevity shifts the population risk profile:
People now live longer, so there is greater time window for chronic diseases to develop; aging is strongly linked to chronic disease onset.
Industrialization and environmental factors increase chronic risk:
Pollutants, higher stress, occupational hazards, and lifestyle changes contribute to chronic disease risk.
Summary: infectious disease mortality declined while chronic diseases became more prominent due to improvements in public health and aging populations, along with environmental and lifestyle changes. The timeframe for chronic dominance is roughly 1940-1950 onward in many industrialized countries.
Data context: leading causes of death (CDC data, 2022–2023)
A CDC-based graph (data for 2022 and 2023) shows the 10 leading causes of death in the United States, with eight of the ten being chronic diseases.
Exercise prompt used in class: students choose two or three illnesses circled in red and brainstorm potential causes based on their current knowledge; emphasis on evaluating causes beyond pure biology.
Takeaway: real-world data illustrate the dominance of chronic diseases and the limitations of a purely biomedical explanation for these conditions.
The biopsychosocial model: components and rationale
The biopsychosocial model integrates three interacting domains:
Biological factors: genetic predispositions, inherited conditions, structural abnormalities, age, sex; examples include the BRCA2 mutation, heart-valve malformation; age and sex differences.
Psychological factors: cognition, emotions, motivation; personality traits (e.g., conscientiousness) and their association with health behaviors; the mental processes people bring to illness perception and coping.
Social factors: social environment and physical environment; family, friends, community; access to resources like groceries; societal values; food deserts; stigma; peer influences; urban design and transportation; access to healthcare and support systems.
The term “systems approach” emphasizes that health outcomes arise from interactions among biological, psychological, and social factors rather than a single cause.
Examples to illustrate biopsychosocial factors:
Biological: BRCA2 mutation increases breast/ovarian cancer risk; congenital heart valve defects.
Psychological: deliberate choices influenced by cognition and motivation; stress appraisal and coping; conscientiousness linked to healthier behaviors.
Social: food deserts limit healthy dietary options; peer pressure can both undermine and support healthy behaviors; societal norms around smoking changes over time.
The biopsychosocial model in action: the John A vs John B examples (systems thinking)
John A: inherited heart disease risk plus low socioeconomic status; multiple jobs; limited access to healthy foods; high chronic stress; delayed medical care; risk factors accumulate; eventually develops heart disease.
John B: same genetic risk but higher SES; access to sports, nutrition, and healthcare; stable finances; less chronic stress; supports healthy lifestyle; delays or avoids disease onset; does not develop heart disease.
Lesson: identical biology can lead to different health outcomes due to social and psychological contexts; demonstrates the holistic, interacting nature of health under a systems framework.
Reframing clinical encounters: from biomedical to biopsychosocial
Many people have experienced predominantly biomedical care (focus on symptoms and biological tests) rather than a patient-centered biopsychosocial approach.
The instructor invites students to reflect on their own experiences: have you encountered a biopsychosocial approach in a doctor’s visit?
The aim is to move toward patient-centered care, addressing not only biological signs but also psychosocial context and supports.
Jessica vignette: applying the biopsychosocial lens to a potential cancer case
Recap of Jessica’s presentation: swollen underarm lymph nodes, unintentional weight loss, a breast lump; urgent appointment with a doctor is sought.
Original student task: list additional questions you would ask Jessica if you were her doctor to gather more information.
Sample student ideas (captured from the discussion):
Psychological and social factors: stress level, life changes, day-to-day mental/physical health, social support, motivation to seek help.
Lifestyle and diet: what type of foods she’s eating; daily routines; access to nutritious foods.
Medical history: age, past medical history, family history of cancer, current health problems.
Symptom specifics: duration of symptoms, presence of pain, location (e.g., breast), and onset timeline.
Additional questions proposed after applying biopsychosocial lens:
Social: whether Jessica has support from friends/family, how they responded to her symptoms, access to care.
Psychological: her emotional response to symptoms, level of stress, coping mechanisms, motivation for seeking care.
Life context: job stress, caregiving responsibilities, and daily responsibilities that could influence health and care-seeking.
Practical considerations: access to nutritionally balanced meals, transportation to healthcare, financial resources for treatment, coverage for testing.
Potential non-biomedical treatment considerations if cancer is diagnosed:
Referrals to specialists and additional imaging (e.g., MRI or ultrasound) to refine diagnosis and plan.
Surgical options (e.g., removal) and biopsy to confirm diagnosis.
Radiation therapy or systemic therapies (e.g., chemotherapy) as part of treatment planning.
Emphasis on psychosocial support: mental health resources, support groups, social work involvement.
Consideration of practical supports: financial assistance, transportation, access to nutrition resources, and potential clinical trials.
The discussion highlights how social and psychological contexts shape both diagnosis and treatment planning, reinforcing the biopsychosocial approach.
Synthesis: key distinctions, applications, and implications
The biomedical model:
Focuses on biology as the sole or primary cause of illness; disease is explained by biological factors and treated with biomedical interventions.
Rooted in mind–body dualism and reductionism; well-suited for infectious diseases where pathogens and biology are central.
The biopsychosocial model:
Takes a systems perspective, incorporating biological, psychological, and social factors and their interactions.
Emphasizes patient experience, context, and environment in both understanding illness and in clinical decision-making.
Is considered the dominant approach in health psychology today; aims to address barriers to care, adherence, and overall well-being.
Implications for practice:
Health care should integrate patient context, including stress, social supports, financial constraints, and access to resources, into diagnosis and treatment planning.
Public health and clinical strategies should address social determinants of health, not just biological risk factors.
Ethical considerations include respect for patient experiences, equitable access to care, and consideration of patients’ lived realities in treatment options.
Quick study prompts and takeaways
Distinguish biomedical vs biopsychosocial models and give one concrete example of each.
Describe the four factors that contributed to chronic diseases becoming the leading cause of death in the US and other industrialized nations.
List and give examples of each factor in the biopsychosocial model (biological, psychological, social).
Explain, with a concrete scenario, how the biopsychosocial model would alter diagnosis and treatment planning compared to a strictly biomedical approach.
Reflect on your own clinical experiences or expectations: have you encountered biopsychosocial elements in real-world health care?
Final reflection and assignment details
The instructor plans an in-class exercise where students respond to learning objectives as if they were test questions, to reinforce memory and application:
Name and differentiate the biomedical vs biopsychosocial models from memory.
Explain the infectious vs chronic disease distinction and outline four reasons chronic disease overtook infectious disease as leading causes of death in the US.
Describe and provide examples of each biopsychosocial factor and how they interact (no need to repeat the Jessica application here).
Email the responses to demonstrate engagement and understanding, rather than for strict grading of accuracy.
The class concludes with an emphasis on shifting toward a patient-centered approach in health care, integrating biological, psychological, and social considerations.
Quick glossary and key terms
Biomedical model: disease explained by biology alone; excludes psychological and social factors.
Biopsychosocial model: disease explained by a system of biological, psychological, and social factors and their interactions.
Mind–body dualism: separation of mind and body in explanations of illness.
Reductionism: complex phenomena explained by a single factor (biology in health contexts).
Systems approach: interaction of multiple factors producing health outcomes; non-reductionist.
Infectious disease: acute illness caused by pathogens (bacteria/viruses).
Chronic disease: long-lasting, progressive illnesses that persist and worsen over time.
Food desert: area with limited access to affordable, nutritious food.
BRCA2: a gene mutation associated with higher risk for certain cancers.
References and prompts for further study
Review the two philosophical foundations of the biomedical model: mind–body dualism and reductionism.
Read about George Engel (1977) and the original development of the biopsychosocial model; consider his critique of the biomedical approach and the call for patient-centered care.
Examine CDC data on leading causes of death for 2022 and 2023 and consider how the distribution emphasizes chronic diseases.
Reflect on real-world clinical scenarios you have experienced or observed where a biopsychosocial perspective might have changed the management strategy.
Learning Session Overview
The class focuses on illustrating lecture structure, class expectations, and learning objectives.
Objectives: Differentiate biomedical and biopsychosocial models, distinguish infectious from chronic diseases, describe biopsychosocial factors, and apply the biopsychosocial model to diagnosis and treatment.
Learning objectives on slides act as a study guide, highlighting major points.
The Biomedical Model: Core Concepts
Definition: Suggests disease and illness are purely biological.
Focus: Biological factors, largely excluding psychological and social factors.
Philosophical Roots:
Mind–body dualism: Mind and body are separate; mind has minimal influence on physical health.
Reductionism: Complex phenomena (e.g., diseases) are explained by a single, simple factor (biology).
Application: Especially effective for infectious diseases.
Infectious vs. Chronic Disease
Infectious Diseases:
Acute, sudden onset illnesses caused by pathogens (bacteria, viruses).
Examples: Common cold, flu, tuberculosis, COVID-19.
Chronic Diseases:
Long-lived, degenerative illnesses that worsen over time and persist.
Examples: Cancer, heart disease, diabetes, arthritis.
Key Distinction: Infectious diseases are often addressed with vaccines, antibiotics/antivirals; chronic diseases reflect long-term risk factors and lifestyle.
Four Reasons Chronic Disease Overtook Infectious Diseases
Prevention Measures: Access to clean water, water/sewage treatment reduced infection risk.
Vaccines: Drastically reduced diseases like polio and measles.
Increased Longevity: People live longer, increasing time for chronic diseases to develop; aging is linked to chronic disease onset.
Industrialization and Environmental Factors: Pollutants, stress, occupational hazards, and lifestyle changes contribute to chronic disease risk.
This shift occurred roughly from 1940-1950 onward in industrialized countries.
The Biopsychosocial Model: Components and Rationale
Definition: Integrates three interacting domains:
Biological factors: Genetic predispositions, inherited conditions, structural abnormalities, age, sex (e.g., BRCA2 mutation and cancer risk).
Psychological factors: Cognition, emotions, motivation, personality traits, impact of stigma (e.g., conscientiousness and health behaviors, stress appraisal).
Social factors: Family, friends, community, physical environment, access to resources, societal values (e.g., food deserts, peer influence).
Systems Approach: Emphasizes that health outcomes arise from interactions among these factors, not a single cause.
Application (John A vs. John B): Identical genetic risk can lead to different outcomes based on socioeconomic status, resources, stress, and lifestyle opportunities, demonstrating the holistic nature of health.