When someone receives a diagnosis of a chronic illness, the impact goes far beyond physical symptoms. Daily routines shift, relationships change, and deeply held assumptions about the future get challenged. How people navigate this experience – whether they struggle or find a way to adapt – is shaped by a complex web of psychological, social, and biological factors. Over decades of research, psychologists and health professionals have developed a range of theories to explain this process. Each model illuminates a different piece of the puzzle, and together they form a rich, nuanced picture of what psychosocial adjustment to chronic illness actually involves.
Table of Contents
- The biomedical model: where adjustment theory began – and its limits
- Engel’s biopsychosocial model: a foundational shift
- Wagner’s chronic care model: organizing healthcare around the whole person
- Lazarus and Folkman’s stress and coping model: the role of appraisal
- Livneh’s stage model: adjustment as a process over time
- The recurrent model: adaptation as dynamic and cyclical
- Ecological models: the social environment as a factor in adjustment
- Leventhal’s common sense model: illness representations and self-regulation
- Moos and Holahan’s model: personal resources and adaptive tasks
- Why multiple models matter
The biomedical model: where adjustment theory began – and its limits
For most of the twentieth century, medicine operated on a straightforward premise: illness is a malfunction in the body’s biological machinery, and treatment means fixing that malfunction. This is the essence of the biomedical model. It produced enormous advances in surgery, pharmacology, and diagnostics. But it also had a fundamental blind spot.
As critics like Antonovsky (1979) and Mirowsky and Ross (2002) pointed out, the biomedical model reduces individuals to their diseases. It focuses on anatomical and physiological dysfunction while largely ignoring the person’s emotional state, their social relationships, their sense of identity, and the cultural context in which they live. For someone managing a condition like rheumatoid arthritis or multiple sclerosis, this narrow lens misses most of what matters in daily life. The biomedical model over-emphasized technical procedures and laboratory measurements at the expense of patients’ reported experiences of their own symptoms. The inadequacy of this framework created the intellectual space for richer, more comprehensive theories to emerge.
Engel’s biopsychosocial model: a foundational shift
In 1977, psychiatrist George Engel published a landmark paper arguing that medicine needed a new model – one that could account for the full human experience of illness. His biopsychosocial model (BPSM) proposed that biological, psychological, and social factors all interact to produce illness and shape recovery.
The model builds on the idea that illness and health result from an interaction between biological, psychological, and social factors. Biological factors include genetics, physiology, and the direct effects of disease processes. Psychological factors cover thoughts, emotions, and behaviors – including how someone interprets their diagnosis and manages distress. Social factors encompass family dynamics, cultural beliefs, socioeconomic status, and access to healthcare.
What made Engel’s model so influential was its insistence that these three domains are not independent – they interact continuously. A change at the subcellular level, such as a viral infection, has the potential to affect organ function, the person, the family, and society. Similarly, a change at the interpersonal level, such as the death of a spouse, can affect psychological status, cellular immunity, and ultimately disease susceptibility. The biopsychosocial model is now the basis of the World Health Organisation’s International Classification of Functioning and is widely used in clinical guidelines and research into rehabilitation and chronic pain.
Wagner’s chronic care model: organizing healthcare around the whole person
The Chronic Care Model, developed by Edward Wagner (1998), took a more practical, systems-level approach. Wagner recognized that managing a long-term condition like diabetes or heart failure cannot rely on sporadic clinical appointments. Effective care requires a proactive, coordinated system built around the patient’s ongoing needs.
The model integrates several components: access to community resources and support policies, well-organized healthcare delivery, decision support for clinicians, clinical information systems, and – critically – self-management support. This last element is central. Patients who are empowered with knowledge, skills, and confidence to manage their own conditions are far more likely to achieve good outcomes. A 2018 review found that applying this kind of integrated approach in primary care could lead to improved clinical outcomes by creating awareness of factors impacting health and enhancing patients’ self-management of their illnesses. Wagner’s model shifted the conversation from what clinicians do to patients toward what patients, families, and communities can do together with healthcare providers.
Lazarus and Folkman’s stress and coping model: the role of appraisal
Perhaps no theory has been more widely applied to understanding adjustment than Lazarus and Folkman’s transactional model of stress and coping (1984). Its core insight is deceptively simple: what matters is not how objectively severe a stressor is, but how the individual perceives and appraises it.
According to Lazarus, the effect that stress has on a person is based more on that person’s feeling of threat, vulnerability, and ability to cope than on the stressful event itself. The model identifies two sequential appraisal processes. In primary appraisal, a person evaluates whether a situation poses a threat, challenge, or harm to their wellbeing. In secondary appraisal, they assess what coping resources – practical, social, and psychological – are available to them. As the individual and environment dynamically interact, initiating coping strategies prompts ongoing reappraisal of the situation.
From this appraisal process, two broad coping strategies emerge. Problem-focused coping involves taking direct action to change or manage the stressor – researching treatment options, restructuring work schedules, or seeking specialist care. Emotion-focused coping involves regulating the emotional distress caused by the stressor – through acceptance, reframing, or seeking emotional support. People tend to use more problem-focused strategies when a situation is appraised as changeable, and more emotion-focused strategies when it is appraised as less changeable. Both types of coping are typically used in any given stressful encounter.
Livneh’s stage model: adjustment as a process over time
Not all adjustment happens at once. Hanoch Livneh (1991) proposed a stage model describing how people typically move through distinct psychological phases following the onset of a chronic illness or disability. Drawing from earlier grief and loss literature, Livneh identified five broad stages:
Shock – the initial numbing response to the diagnosis. Anxiety – a period of heightened distress and uncertainty about the future. Denial – a protective refusal to fully accept the reality of the condition. Depression and internalized anger – a deeper reckoning with loss, including loss of former functioning and roles. Acknowledgment and reintegration – a gradual acceptance of the condition and a reorganization of identity and life goals around the new reality.
Livneh was careful to note that this is not a rigid linear sequence. People may revisit earlier stages, skip some entirely, or cycle through them repeatedly – particularly during flare-ups or new complications. The stage model is most useful as a descriptive framework that helps clinicians and patients recognize that distress following diagnosis is normal, expected, and – in most cases – temporary.
The recurrent model: adaptation as dynamic and cyclical
Davis (1987) offered an important corrective to linear stage thinking with the recurrent model of adaptation. Rather than moving steadily from shock toward reintegration, adjustment is better understood as a dynamic, ongoing process. New challenges – a worsening of symptoms, a treatment failure, a change in functional capacity – can trigger fresh cycles of appraisal and adaptation.
A central mechanism in this model is the development of cognitive schemas: mental frameworks people use to make sense of their illness and its place in their lives. As new information arrives and circumstances change, these schemas are updated. This updating process is not always smooth or comfortable, but it is what allows individuals to maintain psychological equilibrium over the long course of a chronic condition. The recurrent model captures something that purely stage-based accounts often miss: that adjustment is not a destination but an ongoing, iterative process.
Ecological models: the social environment as a factor in adjustment
Beatrice Wright (1983) and other ecological theorists argued that adjustment to disability cannot be understood by looking only at the individual. The social environment – including community attitudes, institutional structures, and cultural norms – plays a powerful role in shaping how a person with a chronic condition experiences their situation.
If a person with mobility impairment lives in a city with accessible public transport and inclusive workplaces, their adjustment trajectory will look very different from someone in an environment that systematically excludes them. Stigma, discrimination, and social isolation are not merely psychological experiences – they are environmental conditions that actively shape outcomes. Ecological models align closely with the World Health Organization’s International Classification of Functioning, Disability and Health (ICF), which frames disability as the product of an interaction between a health condition and contextual factors – environmental as well as personal.
Leventhal’s common sense model: illness representations and self-regulation
Howard Leventhal and colleagues developed the Common Sense Model (CSM) of self-regulation, which focuses on the cognitive and emotional representations people form about their illnesses and how these representations drive behavior.
The model proposes a hierarchically organized adaptive system featuring three main constructs: the representation of the illness experience, action planning or coping responses, and appraisal – the monitoring of the success or failure of coping efforts. According to Leventhal, individuals construct beliefs about their illness across five key dimensions: identity (what they think the illness is called and what symptoms belong to it); timeline (how long they expect it to last); consequences (what impact it will have on their life); cause (what they believe brought it on); and controllability (whether they believe it can be managed or cured).
Illness representations are constructed over time from personal and vicarious experience, and from social and cultural knowledge of the illness. They are a temporarily available mental model informed by currently available information. These representations directly shape coping choices. A person who believes their condition is controllable and time-limited is likely to engage more actively in treatment. Illness representations determine a person’s appraisal of an illness situation and their health behavior, and they can lead to emotion-based coping behavior when individuals develop strong emotional reactions to the health threat. The CSM has been applied extensively in research on conditions ranging from diabetes and hypertension to cancer and chronic pain.
Moos and Holahan’s model: personal resources and adaptive tasks
Rudolf Moos and Charles Holahan (2007) developed a comprehensive framework that maps out the determinants of coping and health outcomes in chronic illness. Their model treats the onset of a chronic condition as what they called an extended life crisis – not a single traumatic event but an ongoing situation demanding continuous adaptation.
According to the model, personal resources, health-related factors, and social and physical context influence how an individual appraises their health condition and formulates adaptive tasks, impacting the choice of coping strategies and health-related outcomes. Personal resources include relatively stable characteristics such as self-efficacy, optimism, and existing coping skills. Social and physical context encompasses family support, healthcare quality, and the broader community environment.
The model identifies two categories of adaptive tasks: illness-related tasks (managing symptoms, navigating treatment demands, preserving relationships with healthcare providers) and general tasks (maintaining a stable self-concept, sustaining close relationships, and managing emotional balance). Moos and Holahan also distinguished coping by its focus – approach versus avoidance – and its type – behavioral versus cognitive – yielding four categories: behavioral approach (seeking social support), cognitive approach (positively reframing the situation), behavioral avoidance (such as substance use), and cognitive avoidance (denial or minimization). Most individuals cope reasonably well with such a crisis and are able to recover and achieve a new equilibrium. Some individuals emerge with a more mature outlook and a richer appreciation of life.
Why multiple models matter
No single theory captures the full complexity of how people adjust to chronic illness. The biomedical model explains the biological substrate but ignores the person. Stage models describe emotional processes but risk implying false linearity. Cognitive models like the CSM reveal how beliefs shape behavior but may underweight social and structural factors. Ecological models correct for this, but can understate the role of individual psychology.
In practice, clinicians, counselors, and rehabilitation professionals draw on several of these frameworks simultaneously. A patient struggling after a diabetes diagnosis may need Lazarus and Folkman’s framework to understand their appraisal patterns, Leventhal’s CSM to examine their illness beliefs, and an ecological lens to identify the environmental barriers limiting their access to care. Together, these models provide a toolkit for understanding – and supporting – one of the most challenging experiences a person can face.
What do you think? Of the models covered here, which do you feel best captures the lived experience of someone adjusting to a long-term health condition – and is there an aspect of that experience you feel none of these theories fully address? If social and environmental factors shape adjustment as powerfully as these ecological models suggest, what does that mean for where responsibility for better outcomes should lie?
Leave a Reply