Psychogenic vs. Biomedical Models
The most consequential debate in ME/CFS history has been whether the illness is fundamentally psychological or biological. This debate has shaped research funding, clinical treatment, and patient experience for decades.
1 Historical Context
The psychogenic model of ME/CFS emerged in the 1970s–1980s, influenced by the observation that no single pathogen could be consistently identified as a cause, that routine laboratory tests were often normal, and that fatigue was associated with depression. The “biopsychosocial” model proposed by Wessely, White, and colleagues framed ME/CFS as a condition perpetuated by deconditioning, illness beliefs, and fear avoidance—treatable through exercise and cognitive restructuring. This model achieved institutional dominance in the UK (through the PACE trial and NICE’s pre-2021 guidelines), influencing insurance decisions, disability assessments, and clinical training. Patients who resisted exercise therapy or psychological treatment were characterized as having “unhelpful illness beliefs.”
The psychogenic framing carries measurable stigma consequences beyond its direct clinical effects. Attribution of ME/CFS to controllable or psychological causes is the strongest predictor of perceived stigma (n=499; Froehlich et al. 2022), and this perceived stigma mediates the relationship between negative causal attributions and worse functional status, social role satisfaction, and health-related quality of life (Froehlich et al. 2022). From the patient perspective, stigma operating through healthcare interactions is often reported as more distressing than the physical symptoms themselves (Terman, Cotler, and Jason 2019) (Deale and Wessely 2001).
The persistence of this framing is documented even in the post-COVID era. Ranque and Cogan (2025) published a narrative review in Frontiers in Medicine arguing that long COVID should be managed primarily as a “functional somatic disorder” (FSD), treatable through CBT and graded exercise (Ranque and Cogan 2025). They reported an online survey of 240 French senior internists in which 89% endorsed FSD as a possible cause of long COVID, 63% selected it as the primary cause, and only 9% identified a biological mechanism. Notably, 46% reported unwillingness to continue managing long COVID patients after negative standard workups, and 29% preferred not to see long COVID patients at all. The survey does not demonstrate a biological or clinical mechanism—it documents the depth to which the functional paradigm has been internalized by a substantial segment of the medical profession, shaping clinical encounters before the evidence has been fully evaluated.
2 Evidence for Biological Basis
The accumulated biological evidence against a psychogenic model is now overwhelming:
- Immune dysfunction: Reduced NK cell cytotoxicity, T cell exhaustion, altered cytokine profiles, and autoantibodies—none of which are features of psychological conditions (Hardcastle et al. 2016) (Che et al. 2025)
- Metabolic dysfunction: Impaired mitochondrial respiration, hypometabolic state, and cellular energy deficits documented by metabolomics and Seahorse analyzer studies (Naviaux et al. 2016) (Mandarano et al. 2020)
- Autonomic dysfunction: Objective documentation of POTS, orthostatic hypotension, and impaired heart rate variability (Hoad et al. 2008) (Newton et al. 2007)
- Neuroinflammation: PET imaging demonstrating microglial activation (Raijmakers et al. 2021)
- Neurotransmitter deficiency: CSF catecholamine deficiency documented by the NIH study (Walitt et al. 2024)
- Objective exercise intolerance: Two-day CPET demonstrating measurable physiological deterioration after exertion—impossible to produce through psychological mechanisms—though group-average VO₂ decline is contested (positive studies (Keller et al. 2024) vs null replication (Mancini et al. 2026)); elevated RPE and chronotropic incompetence are consistent findings across studies
- Physiological (not psychological) PEM features in deep phenotyping: The NIH deep-phenotyping study, sometimes cited to support a psychological explanation of PEM, in fact documented multiple physiological abnormalities—autonomic dysfunction, differential cerebrospinal fluid catecholamine and metabolite profiles, and lower post-exercise cortisol responses—and found that peak measures did not correlate with effort preference (Walitt et al. 2024) (Appelman et al. 2025). This is inconsistent with the claim that effort avoidance dictates V̇O2max or explains PEM.
3 The Role of Psychological Factors
Acknowledging the biological basis of ME/CFS does not deny that psychological factors affect the patient experience. Depression, anxiety, and trauma are common—as consequences of chronic disabling illness, not as causes. Psychological suffering deserves treatment in its own right, but psychological treatment cannot address the underlying pathophysiology. The critical distinction is between “ME/CFS causes psychological distress” (correct) and “psychological distress causes ME/CFS” (unsupported).
4 Patient Advocacy and the Psychogenic Harm
The psychogenic model has caused measurable harm to patients:
- Treatment harm: GET prescribed under the psychogenic model has worsened many patients (Kindlon 2011)
- Diagnostic delay: Physicians trained to view ME/CFS as psychological often fail to diagnose or investigate the condition, resulting in years of delayed treatment. The diagnostic labyrinth is well-documented—across 12 qualitative studies, patients report navigating systems where their symptoms are repeatedly dismissed as psychological, somatoform, or not severe enough to warrant investigation (Bayliss et al. 2014)
- Insurance and disability denial: Patients report that psychogenic framing has contributed to denial of disability benefits and insurance claims
- Research underfunding: Classification as a psychological condition reduced biomedical research funding for decades
- Stigma: Patients report that the psychogenic label is the single most damaging aspect of their interaction with the medical system, more distressing than the illness itself. Perceived stigma independently predicts suicidal ideation after controlling for depression (McManimen et al. 2018) (Johnson et al. 2022). The healthcare dismissal experience—being disbelieved, trivialised, or labelled—is the most consistent finding across qualitative research spanning 1999–2024 (Asbring and Närvänen 2002) (Guise, McVittie, and McKinlay 2010) (Melby and Nair 2024)
- Media reinforcement: Content analysis of 280 UK newspaper articles found 70% emphasised psychological characterisations of ME/CFS, amplifying public stigma (Knudsen et al. 2011)
- Name-based stigma: The diagnostic label “chronic fatigue syndrome” generates more negative attributions than alternative names, indicating the illness name itself propagates stigma (Jason et al. 2002) Patient advocacy organizations have been instrumental in challenging the psychogenic model, demanding data transparency (PACE trial reanalysis), and advocating for guideline changes. The 2021 NICE guideline revision (National Institute for Health and Care Excellence 2021), which explicitly rejected the biopsychosocial model for ME/CFS, represents a landmark victory for evidence-based medicine driven in significant part by patient advocacy. The academic counterargument continues to build. Spanoghe, Molmans et al. (2026) published a peer-reviewed commentary in Frontiers in Medicine directly rebutting the FSD framing proposed by Ranque and Cogan (Spanoghe et al. 2026). Their critique identifies five structural weaknesses in the FSD position: (1) the original article is a narrative review without systematic evidence evaluation, risk-of-bias assessment, or GRADE-quality hierarchisation; (2) the FSD concept itself has poorly defined boundaries, heterogeneous criteria, and functions as a residual category rather than a well-delimited diagnostic entity; (3) the literature selection omits substantial biomedical evidence including viral persistence, neuroinflammation, endothelial dysfunction, skeletal muscle abnormalities, mitochondrial dysfunction, and autonomic impairment; (4) attributing primary etiological weight to psychological factors without longitudinal or causal analyses risks confusing consequences with causes; and (5) framing long COVID as predominantly psychosomatic in a context of scientific uncertainty causes measurable harm—distress, self-doubt, loss of agency, and isolation. The authors advocate instead for treating long COVID as a heterogeneous post-infectious multisystemic condition requiring biomedical sub-classification, mechanistic investigation, and targeted interventions.
Schomerus et al. (2026) articulate five specific, interconnected harms that follow from psychologizing LC and ME/CFS, whether primary or secondary:
Harm 1: Iatrogenic deterioration from activation therapy. A psychological attribution implies that deconditioning, avoidance, and illness beliefs must be treated with graded activity. Patient surveys document that 72% of LC respondents reported “damaging or incorrect treatments, predominantly activating therapies during rehabilitation or medical recommendations to exercise” (Hammer et al. 2025). The US patient survey by Eckey et al. (2025, n=3,867) found that 50% of those who experienced graded exercise therapy reported substantial worsening, with a further 30% reporting moderate or mild deterioration; only 10% experienced any improvement (Eckey et al. 2025). These harm reports are biologically anchored: PEM is driven by impaired energy metabolism (Chapter Energy Metabolism and Mitochondrial Function) and exertion above the lowered threshold produces measurable tissue damage (Appelman et al. 2024).
Harm 2: Invalidation of illness experience. When symptoms are framed as products of dysfunctional illness beliefs rather than biological disease, the patient’s body perception—their only available instrument for managing PEM through pacing—is pathologized. Psychologization undermines the patient’s capacity for self-management by reclassifying pacing as “avoidance” and genuine PEM as “catastrophizing” (Section Inflammation Changes How the Brain Senses the Body). Büchner et al. (2025, n=1,156) found that 46.8% of LC patients were told their symptoms were psychological; this experience was strongly associated with perceived stigma (\(p < 0.001\)) and mediated worse mental health outcomes (Büchner et al. 2025).
Harm 3: Neglect of biomedical diagnosis and treatment. A psychological framework reduces the perceived need for biomedical investigation. Individual symptoms and comorbidities—POTS (postural orthostatic tachycardia syndrome), MCAS (mast cell activation syndrome), orthostatic hypotension—are somatically treatable in many cases, yet patients report that psychosomatic attribution prevents appropriate workup. The D-A-CH consensus explicitly recommends systematic exclusion of treatable somatic conditions before considering psychiatric differentials (Hoffmann et al. 2024). A psychological “F-diagnosis” can produce negative cascading effects across treatment, employment law, and insurance as physical complaints receive less attention in the presence of psychiatric labels—a well-documented pattern called diagnostic overshadowing, where a mental health label reduces the perceived need to investigate physical symptoms.
Harm 4: Medico-legal disadvantage. In disability assessment, insurance evaluation, and workers’ compensation, the assumption of psychological causation is practically unfalsifiable: rejection of the psychosomatic disease model is itself interpreted as evidence of its relevance (lack of insight, somatization). Unlike in therapeutic contexts where the patient can decline an unhelpful model, in medico-legal settings the attribution carries binding consequences.
Harm 5: Family and social harm. The same logic that pathologizes patients also pathologizes their caregivers. Parents of children with ME/CFS who protect their child from activity that triggers PEM can be accused of facilitating avoidance, reinforcing illness behavior, or even perpetrating Münchhausen-by-proxy syndrome—with documented cases of child protection proceedings and loss of custody (Schomerus et al. 2026). Similar dynamics affect adult children caring for parents with ME/CFS and parents with ME/CFS who are assessed for childcare capacity.
(Certainty: 0.70 for the existence of each documented harm (individually supported by quantitative surveys, clinical consensus, and qualitative evidence per above). The framework’s claim that these harms are causally mediated by psychologization — rather than generic to contested illness — has not been formally validated. A simpler alternative hypothesis is that any contested chronic illness generates similar harms; psychologization is one form of contested-illness dismissal, and the harms it produces may not be psychologization-specific. The framework is strongest when read as a taxonomy of documented harms requiring prospective testing of causal links. Replication status: partially — each sub-component has independent supporting evidence, but the framework as a whole and its causal claims have not been empirically validated against alternative models. Falsifiability: The framework predicts that psychologization exposure → functional decline is mediated by pacing disruption (Harm 2), testable via the prospective cohort design proposed in Prospective Cohort of Psychologization → Functional Decline. The framework would be weakened if psychologization exposure does not independently predict functional decline after controlling for objective baseline severity, or if a generic “contested illness” measure predicts decline equally well.)
Drug trials routinely monitor and report adverse events as a regulatory requirement, but psychosocial intervention trials for ME/CFS — despite evidence that activation-based approaches cause harm in a substantial minority of patients — operate under far laxer standards. The general pattern of inadequate harm monitoring in GET/CBT trials is independently documented: Kindlon (2011, (Kindlon 2011)) found systematic underreporting of harms in ME/CFS psychosocial trials, and Cooper et al. (2025, (Cooper and Papadopoulos 2025)) demonstrated via systematic review that GET carries a 3–5× higher harm rate than pacing. Schomerus et al. (2026) note a parallel pattern in LC psychotherapy trials: a systematic review found that most included studies provided no adverse effects information — though this specific statistic (reported as a secondary citation within the Schomerus essay) should be treated with caution pending dedicated independent verification (Schomerus et al. 2026). PEM, the decisive clinical parameter for safety, is frequently not assessed or not assessed differentially as an adverse outcome in psychosocial trials. Many studies lack control groups, making it impossible to distinguish genuine treatment effects from spontaneous recovery or non-specific effects such as placebo and natural history.
This regulatory gap may reflect divergent institutional histories (drug and behavioural intervention trials evolved under different regulatory systems) and genuine measurement challenges (defining adverse events in psychosocial trials is inherently harder than in drug trials) rather than deliberate neglect. Regardless of the cause, the consequence is the same: inadequate safety data for interventions actively prescribed to a population where harm rates in patient surveys range from 51–74% (Kindlon 2011).
(Certainty: 0.65. The general pattern of inadequate monitoring is independently documented by Kindlon (2011) and Cooper (2025). The specific LC psychotherapy statistic is a secondary citation within Schomerus 2026 — the general pattern is well-supported without relying on it. The regulatory-asymmetry claim (different safety standards for drug vs psychosocial trials) is a structural/regulatory fact, not an empirical hypothesis. Falsifiability: a dedicated systematic review of adverse event reporting in all published ME/CFS psychosocial intervention trials would establish the rate of adequate safety monitoring and either confirm or revise the specificity of the claim. Origin: literature — derived from Schomerus 2026’s argument, with supporting evidence from Cooper 2025.)
The single most important evidence gap: no longitudinal study has prospectively measured psychologization exposure and tracked functional decline while accounting for other factors that might explain the link. Büchner 2025 is cross-sectional (n=1,156); all other cited studies are qualitative or cross-sectional. Proposed: n ≥ 500 newly diagnosed, 36-month follow-up, quarterly assessments including psychologization exposure, SF-36, actigraphy, PEM frequency, CPET, and biomarker panel. Primary analysis: statistical model testing baseline psychologization as predictor of functional trajectory after controlling for objective severity measures.