The chronic fatigue syndrome (Chronic Fatigue Syndrome, CFS) is a complex pathological condition characterized by prolonged fatigue, persistent and debilitating, and other nonspecific symptoms, with negative and restrictive consequences on the physical and psychological functioning.
It must be present for at least 6 months, with a course not necessarily permanent, but with a definite onset (Sharpe et al., 1991). There is currently no tool that allows to assess the presence of the Syndrome. For this reason, it is a diagnosis that is made mainly by excluding other psychopathologies.
Although chronic fatigue syndrome and depression may appear to be overlapping in some respects, research has suggested that the former has distinct cognitive characteristics (Moss-Morris & Petrie, 2001).
However, research has also found that anxiety , depression and transient negative affect are significantly associated with the aggravation of fatigue in chronic fatigue syndrome (Sohl & Friedberg, 2008).
Currently, no specific biological etiology has been identified for CFS and can thus be considered within the spectrum of clinically unexplained symptoms.
A large number of studies have focused on the cognitive processes involved in this syndrome. Some of these have found an association between a self-reported tendency to focus on symptoms and disease-related disability in patients with chronic fatigue syndrome (Ray, Jefferies, & Weir, 1995, 1997; Vercoulen et al., 1998 ).
Furthermore, recent studies have supported the hypothesis that CFS may be characterized by a persistent and dysfunctional thought process associated with CAS (Cognitive Attentional Syndrome).
Indeed, there would be interpretative bias in somatic information processing (Moss-Morris & Petrie, 2003), high levels of health-related brooding, and health threat concerns (Aggarwal, McBeth, Zakrzewska, Lunt, & MacFarlane, 2006).
Finally, attentional biases in the processing of health threatening stimuli would be present in patients with chronic fatigue syndrome (Hou, Moss-Morris, Bradley, Peveler, & Mogg, 2008). These findings have been useful in explaining the crucial role of cognitive and attentional processes involved in chronic fatigue syndrome ; however the beliefs by which these processes are influenced have yet to be specified.
Two types of metacognitive beliefs have been hypothesized to be useful in predicting the severity of chronic fatigue symptoms and impairment in physical functioning (Maher ‐ Edwards, Fernie, Murphy, Wells, & Spada, 2011):
- beliefs about the need to control thoughts, which could contribute to the maintenance of persistent and negative interpretations about symptoms and to the activation of maladaptive coping strategies (e.g. rumination, thought suppression and brooding) which would contribute to cognitive overload, executive disability and feelings of mental and psychological fatigue;
- beliefs about a lack of confidence in cognitive competence, which would contribute to the severity of symptoms, limiting the choice and implementation of adaptive coping strategies.
Starting from these discoveries, several studies have dealt with the main cognitive-behavioral treatments potentially implicated in the treatment of CFS.
The main ones are the cognitive-behavioral therapy model (CBT) and the therapy model based on the execution of gradual physical exercises (GET). The CBT model deals with the factors that can predispose (e.g. perfectionism), trigger (e.g. virus, stress, and / or trauma), and maintain (e.g. stress, negative emotions, or all-nothing behavior patterns) symptoms in chronic fatigue syndrome .
Changes in avoidance behaviors and related beliefs are associated with successful CBT outcome (Deale, Chalder and Wessely, 1998).
The GET model for CFS is based on the concept of deconditioning. After exposure to an initial CFS trigger (e.g. a viral infection), maladaptive coping responses (e.g. sleep to recover) are deconditioned.
Patients are encouraged to establish a “baseline exercise” (for an exercise duration that does not lead to exacerbation of symptoms) and gradually increase duration first and then intensity.
The mechanism of change in GET is based on the modification of the interpretation about somatic sensations (Moss-Morris, Sharon, Tobin and Baldi, 2005). Randomized controlled trials (RCTs) have demonstrated evidence of efficacy of such treatments (Moss-Morris et al., 2005; Prins et al., 2001).
Recent research (Fernie, Murphy, Wells, Nikcevic & Spada, 2016) has made it possible to compare these two treatments for chronic fatigue syndrome considered most effective in clinical practice, CBT (Cognitive Behavioral Therapy) and GET (Graded Excercise Therapy), building on the findings of the PACE trial (White et al., 2011).
They also provided evidence of the effectiveness of these treatments, which appear to reduce fatigue, anxiety, depression, as well as increase physical functioning.
Previous studies had already shown how by combining cognitive behavioral therapy (CBT) and the execution of gradual physical exercises (GET) with specialized medical care (antidepressant-based therapies and low-dose non-steroidal anti-inflammatory drugs, SMC), recovery was achieved. three times more chronic fatigue symptoms than with SMC therapy alone (Sharpe et al., 2015).
The 2016 study by Fernie et al. it also examined whether metacognitive change, measured with the Metacognitions Questionnaire-30 (MCQ-30), could be considered a significant predictor of treatment outcome.
However, while it is possible that the hypothesized meta-beliefs were indirectly addressed in CBT, it is unlikely that they were addressed in GET (Wells, 2011).
Negative beliefs about uncontrollable and dangerous thoughts could lead to negative evaluations of cognitive experiences, such as to activate perseverative thought processes (e.g. brooding) and physical changes capable of altering perceived physical fatigue and the beneficial properties of rest, as well as contributing to mental fatigue.
Otherwise, the relationship between such beliefs and changes in fatigue severity could reflect a decrease in brooding and worrying symptoms, variables that appear to mediate treatment outcomes in GET (Moss-Morris et al., 2005).
Meta-beliefs related to cognitive incompetence may reflect the cognitive difficulties reported by subjects with chronic fatigue syndrome . The improvements in these cognitive factors could be due to the reduction of fatigue itself and the consequent improvement of executive functions such as concentration and memory.
On the other hand, negative meta-beliefs about patients’ cognitive confidence could lead to an inhibition of coping strategies when fatigued.
Despite these considerations, further studies are needed to investigate the role of metacognitive beliefs in the severity levels of chronic fatigue syndrome and the predictive effect they have, net of other variables considered. In addition, in other research, other mediators were considered implicated in therapeutic change.
In particular, the modification of beliefs relating to the avoidance of fear (e.g. the fear that exercise or physical activity could worsen the symptoms and the consequent avoidance of physical activity) and the hyper-focus on fatigue , were considered important for predicting treatment outcome (Chalder, Goldsmith, White, Sharpe and Pickles, 2015).
In conclusion, both CBT and GET (Fernie et al., 2016) have met with high levels of patient satisfaction, suggesting that such treatments are well received despite the controversies they are sometimes associated with in randomized controlled trials.
Finally, these studies suggest the importance of researching specific metacognitive factors that could be implicated in CFS and determine a deepening of this condition, also from a therapeutic point of view.
