title: Sudden vs gradual onset of chronic fatigue syndrome differentiates individuals on cognitive and psychiatric measures.
abstract: To examine the influence of mode of illness onset on psychiatric status and neuropsychological performance, 36 patients with CFS were divided into two groups: sudden vs gradual onset of symptoms. These two CFS subgroups were compared to each other and to sedentary healthy controls on standardized neuropsychological tests of attention/concentration, information processing efficiency, memory, and higher cortical functions. In addition, the distribution of comorbid Axis I psychiatric disease between the two CFS groups was examined. The rate of concurrent psychiatric disease was significantly greater in the CFS-gradual group relative to the CFS-sudden group. While both CFS groups showed a significant reduction in information processing ability relative to controls, impairment in memory was more severe in the CFS-sudden group. Because of the significant heterogeneity of the CFS population, the need for subgroup analysis is discussed.
authors.affiliation: UMDNJ-New Jersey Medical School, Newark, USA.
authors.forename: J
authors.initials: J
authors.lastname: DeLuca
authors.forename: S K
authors.initials: SK
authors.lastname: Johnson
authors.forename: S P
authors.initials: SP
authors.lastname: Ellis
authors.forename: B H
authors.initials: BH
authors.lastname: Natelson
mesh_terms: D003072:Cognition Disorders / Q000175:diagnosis* / Q000523:psychology; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis* / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests