Sudden vs gradual onset of chronic fatigue syndrome differentiates individuals on cognitive and psychiatric measures

J Psychiatr Res. Jan-Feb 1997;31(1):83-90. doi: 10.1016/s0022-3956(96)00052-0.


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.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cognition Disorders / diagnosis*
  • Cognition Disorders / psychology
  • Fatigue Syndrome, Chronic / diagnosis*
  • Fatigue Syndrome, Chronic / psychology*
  • Female
  • Humans
  • Male
  • Neuropsychological Tests