Psychogenic Explanations of Physical Illness: Time to Examine the Evidence

Abstract:

In some patients with chronic physical complaints, detailed examination fails to reveal a well-recognized underlying disease process. In this situation, the physician may suspect a psychological cause. In this review, we critically evaluated the evidence for this causal claim, focusing on complaints presenting as neurological disorders.

There were four main conclusions. First, patients with these complaints frequently exhibit psychopathology but not consistently more often than patients with a comparable “organic” diagnosis, so a causal role cannot be inferred.

Second, these patients report a high incidence of adverse life experiences, but again, there is insufficient evidence to indicate a causal role for any particular type of experience.

Third, although psychogenic illnesses are believed to be more responsive to psychological interventions than comparable “organic” illnesses, there is currently no evidence to support this claim.

Finally, recent evidence suggests that biological and physical factors play a much greater causal role in these illnesses than previously believed. We conclude that there is currently little evidential support for psychogenic theories of illness in the neurological domain. In future research, researchers need to take a wider view concerning the etiology of these illnesses.

Source: Carolyn E. Wilshire and Tony Ward. Psychogenic Explanations of Physical Illness: Time to Examine the Evidence. Perspectives on Psychological Science 2016, Vol. 11(5) 606–631. https://www.researchgate.net/publication/283476227_Psychogenic_explanations_of_physical_illness_Time_to_examine_the_evidence (Full text)

Conceptualising illness and disease: reflections on Sharpe and Greco (2019)

Abstract:

In a recent paper, Sharpe and Greco suggest that chronic fatigue syndrome/myalgic encephalomyelitis (MECFS) can be viewed as an instance of “illness without disease”, and consequently, treatment should be directed towards altering the patient’s experience of, and response to, their symptoms. We discuss two broad issues that arise from Sharpe and Greco’s article, one relating to the assumptions they make about MECFS and its treatment specifically, and the other relating to their conceptualisation of the illness/disease dichotomy.

We argue that the term “illness without disease”, in the sense that Sharpe and Greco use it, is problematic because it can lead to unwarranted causal assumptions. Following these critical comments, we present a new framework for conceptualising the relationship between explanatory disease models and the experience of illness.

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.

Source: Wilshire C, Ward T. Conceptualising illness and disease: reflections on Sharpe and Greco (2019). Med Humanit. 2019 Dec 11. pii: medhum-2019-011756. doi: 10.1136/medhum-2019-011756. [Epub ahead of print] https://www.ncbi.nlm.nih.gov/pubmed/31826926 (Abstract) https://sci-hub.se/10.1136/medhum-2019-011756 (Full article)

Response: Sharpe, Goldsmith and Chalder fail to restore confidence in the PACE trial findings

Abstract:

In a recent paper, we argued that the conclusions of the PACE trial of chronic fatigue syndrome are problematic because the pre-registered protocol was not adhered to. We showed that when the originally specific outcomes and analyses are used, the evidence for the effectiveness of CBT and graded exercise therapy is weak.

In a companion paper to this article, Sharpe, Goldsmith and Chalder dismiss the concerns we raised and maintain that the original conclusions are robust. In this rejoinder, we clarify one misconception in their commentary, and address seven additional arguments they raise in defence of their conclusions.

We conclude that none of these arguments is sufficient to justify digressing from the pre-registered trial protocol. Specifically, the PACE authors view the trial protocol as a preliminary plan, subject to honing and improvement as time progresses, whereas we view it as a contract that should not be broken except in extremely unusual circumstances. While the arguments presented by Sharpe and colleagues inspire some interesting reflections on the scientific process, they fail to restore confidence in the PACE trial’s conclusions.

Source: Carolyn E. Wilshire and Tom Kindlon. Response: Sharpe, Goldsmith and Chalder fail to restore confidence in the PACE trial findings. BMC Psychology20197:19
https://doi.org/10.1186/s40359-019-0296-x© The Author(s). 2019 https://bmcpsychology.biomedcentral.com/articles/10.1186/s40359-019-0296-x (Full article)

Rethinking the treatment of chronic fatigue syndrome—a reanalysis and evaluation of findings from a recent major trial of graded exercise and CBT

Abstract:

Background: The PACE trial was a well-powered randomised trial designed to examine the efficacy of graded exercise therapy (GET) and cognitive behavioural therapy (CBT) for chronic fatigue syndrome. Reports concluded that both treatments were moderately effective, each leading to recovery in over a fifth of patients. However, the reported analyses did not consistently follow the procedures set out in the published protocol, and it is unclear whether the conclusions are fully justified by the evidence.

Methods: Here, we present results based on the original protocol-specified procedures. Data from a recent Freedom of Information request enabled us to closely approximate these procedures. We also evaluate the conclusions from the trial as a whole.

Results: On the original protocol-specified primary outcome measure – overall improvement rates – there was a significant effect of treatment group. However, the groups receiving CBT or GET did not significantly outperform the Control group after correcting for the number of comparisons specified in the trial protocol. Also, rates of recovery were consistently low and not significantly different across treatment groups. Finally, on secondary measures, significant effects were almost entirely confined to self-report measures. These effects did not endure beyond two years.

Conclusions: These findings raise serious concerns about the robustness of the claims made about the efficacy of CBT and GET. The modest treatment effects obtained on self-report measures in the PACE trial do not exceed what could be reasonably accounted for by participant reporting biases.

Source: Carolyn E. Wilshire, Tom Kindlon, Robert Courtney, Alem Matthees, David Tuller, Keith Geraghty and Bruce Levin. Rethinking the treatment of chronic fatigue syndrome—a reanalysis and evaluation of findings from a recent major trial of graded exercise and CBT. BMC PsychologyBMC series. Received: 29 May 2017; Accepted: 22 February 2018; Published: 22 March 2018.  https://doi.org/10.1186/s40359-018-0218-3 (Full article) © The Author(s) 2018.

The problem of bias in behavioural intervention studies: Lessons from the PACE trial

Abstract:

Geraghty’s recent editorial on the PACE trial for chronic fatigue syndrome has stimulated a lively discussion. Here, I consider whether the published claims are justified by the data. I also discuss wider issues concerning trial procedures, researcher allegiance and participant reporting bias. Cognitive behavioural therapy and graded exercise therapy had modest, time-limited effects on self-report measures, but little effect on more objective measures such as fitness and employment status. Given that the trial was non-blinded, and the favoured treatments were promoted to participants as ‘highly effective’, these effects may reflect participant response bias. In non-blinded trials, the issue of reporting biases deserves greater attention in future.

Source: Wilshire C. The problem of bias in behavioural intervention studies: Lessons from the PACE trial. J Health Psychol. 2017 Aug;22(9):1128-1133. doi: 10.1177/1359105317700885. Epub 2017 Mar 23. https://www.ncbi.nlm.nih.gov/pubmed/28805526