Information processing in chronic fatigue syndrome: a preliminary investigation of suggestibility.

This study examines the effects of certain types of information processing on the subjective experience of cognitive deficits in persons with chronic fatigue syndrome (CFS). Two groups of participants, persons with CFS and a group of healthy controls, were administered a symptom inventory and measures of intellectual functioning, memory, automatic processing, and suggestibility. The groups differed significantly on number and severity of reported symptoms and on measures of global suggestibility and automatic processing, but not on measures of intellectual functioning and memory. Suggestibility was related to number and severity of reported symptoms, as well as the inability to inhibit the automatic processing of information. Implications of these findings are discussed, as well as directions for future research and treatment of symptoms associated with CFS.

Chronic fatigue syndrome: identification of distinct subgroups on the basis of allergy and psychologic variables.

BACKGROUND: We investigated a role for allergic inflammation and psychologic parameters in the development of chronic fatigue syndrome (CFS). METHODS: The design was a comparison between subjects with CFS and age- and sex-matched control cohorts. Studies were performed on CFS subjects (n = 18) and control cohorts consisting of normal subjects (n = 11), allergic subjects (n = 14), and individuals with primary depression (n = 12). We quantified cytokines at baseline as cell-associated immunoreactive peptides and as transcripts evaluated by means of semiquantitative RNA-based polymerase chain reactions. Psychologic evaluations included administration of the Diagnostic Interview Schedule, the Structured Clinical Interview, and the Symptom Checklist 90-Revised. RESULTS: Increases in tumor necrosis factor (TNF)-alpha were identified in individual subjects with CFS (50.1 +/- 14.4 pg TNF-alpha per 10(7) peripheral blood mononuclear cells [PBMCs]; mean +/- SEM) and allergic subjects (41.6 +/- 7.6) in comparison with normal subjects (13.1 +/- 8.8) (P < .01 and P < .05, respectively). Similar trends were observed for interferon (IFN)-alpha in allergic subjects (3.0 +/- 1.7 pg/10(7) PBMCs) and subjects with CFS (6.4 +/- 3.4) compared with normal subjects (1.9 +/- 1.4). A significant increase (P < .05) in TNF-alpha transcripts was demonstrated between subjects with CFS and depressed subjects. In contrast to these proinflammatory cytokines, both subjects with CFS (2.6 +/- 1.8 pg/10(7) PBMCs) and allergic subjects (3.4 +/- 2.8) were associated with a statistically significant (P < .01) decrease in IL-10 concentrations compared with normal subjects (60.2 +/- 18.2). As shown in other studies, most of our subjects with CFS were allergic (15 of 18) and therefore presumably demonstrated cytokine gene activation on that basis. The seasonal exacerbation of allergy was associated with a further increase in cellular IFN-alpha (from 2.1 +/- 1.2 to 14.2 +/- 4.5 pg/107 PBMCs; P < .05) but no further modulation of TNF-alpha or IL-10. Similarly, self-reported exacerbations of CFS were associated with a further increase in IFN-alpha (from 2.5 +/- 1.0 to 21.9 +/- 7.8; P < .05) and occurred at times of seasonal exposures to allergens. This linkage does not permit making any definitive conclusions regarding a causative influence of either seasonal allergies or the increase in cellular IFN-alpha with the increase in CFS symptoms. The close association between atopy and CFS led us to speculate that CFS may arise from an abnormal psychologic response to the disordered expression of these proinflammatory and antiinflammatory cytokines. Psychologic variables were predictive of immune status within the CFS sample (65.9% of the variance in immune status; F (3,10) = 6.44, P < .05). Specifically, the absence of a personality disorder but greater endorsement of global psychiatric symptoms was predictive of immune activation. CONCLUSIONS: Most of our subjects with CFS were allergic, and the CFS and allergy cohorts were similar in terms of their immune status. However, the CFS subjects could be discriminated by the distinct psychologic profiles among subjects with and without immune activation. We propose that in at least a large subgroup of subjects with CFS who had allergies, the concomitant influences of immune activation brought on by allergic inflammation in an individual with the appropriate psychologic profile may interact to produce the symptoms of CFS. In a psychologically predisposed individual, symptoms associated with allergic inflammation are recognized as illness.

Cognitive functioning in chronic fatigue syndrome and depression: a preliminary comparison.

This study used a brief battery of neuropsychological measures to examine the performance of patients with chronic fatigue syndrome (CFS) (N = 16) and patients in a major depressive episode (N = 23). The overall neuropsychological performance of the CFS group was not significantly different from depressed patients, and both groups scored within normal limits on most measures. Variability of neuropsychologic performance was in general unrelated to level of depressive symptoms. The results are discussed in terms of the validity of the cognitive criterion for the CFS diagnosis. Subjective complaints of cognitive dysfunction by CFS patients in light of the lack of objective evidence for the same are considered in terms of a somatic vigilance hypothesis.

Effects of perceived sophistication and test validity on acceptance of generalized feedback.

Forty-eight undergraduate females completed a psychological test after they had received instructions that concerned the validity of the test and their sophistication as test takers. Subjects were told that the test was either valuable or worthless in assessing personalities. Subjects also were told that they were either experienced or naive with regard to tests and psychology. Subjects received identical Barnum interpretations, which they rated for accuracy. While the high sophistication subjects rated the interpretation as accurate across validity conditions, the low sophistication subjects rated the interpretation according to the validity instructions they received. These results run counter to previous assertions that validity and sophistication have little or no effect on acceptance of generalized personality feedback.