The relationship between subjective ratings of sleep and mental functioning in healthy subjects and patients with chronic fatigue syndrome

The difference in patterns of motor and cognitive function in chronic fatigue syndrome and severe depressive illness

“…These findings are very much in keeping with previous reports, which have also revealed objective evidence for impairments in verbal fluency (Krupp et al 1994) and other executive tasks (Grafman et al 1993 ;Ray et al 1993 ;Wood et al 1994) ; reaction time (Smith et al 1996 ;Marshall et al 1997 ;Vollmer-Conna et al 1997) ; psychomotor speed (Smith et al 1996 ;Michiels et al 1997) ; and in various measures of attention and memory (Grafman et al 1993 ;McDonald et al 1993 ;Sandman et al 1993 ;Krupp et al 1994 ;Schmaling et al 1994 ;Cope et al 1995 ;DeLuca et al 1995 ;Marcel et al 1996 ;Smith et al 1996 ;Marshall et al 1997 ;Wearden & Appleby, 1997 ;Johnson et al 1998 ;Michiels et al 1998). The effects are modest and show little differential impairment on different test categories.…”

Cognitive deficits in chronic fatigue syndrome and their relationship to psychological status, symptomatology, and everyday functioning.

“…This is consistent with a longitudinal study, which found that improvements on some cognitive tests over time were not related to CFS severity (Tiersky et al, 2001); however, the authors did find a corresponding improvement in fatigue, which the current study did not replicate. Moreover, the deficits in RT were not related to sleep quality; however, it was not possible to examine whether cognitive deficits were restricted to CFS participants with a sleep disorder (as was found by Smith et al, 1996), as only four CFS participants were not classified as poor sleepers. Although high, the finding that 34% of controls were classified as poor sleepers is comparable to the 40% reported for healthy Australian adults of an equivalent age (Magee, Caputi, Iverson, & Huang, 2008).…”

Cognitive functioning in chronic fatigue syndrome: a meta-analysis

“…For example, 13 studies did not provide standard deviations or exact p values for some of the tests, five did not provide data for non-significant findings and one failed to provide data for a single test. All authors were contacted in order to request the missing data, with only four authors providing the necessary data (Smith et al 1996; Claypoole et al 2001; Moss-Morris & Petrie, 2003; Schmaling et al 2003).…”