Date sent:      	Sat, 14 Jul 2001 

Chronic Fatigue Syndrome:  Comorbidity with Fibromyalgia and Psychiatric
Illness

Medicine & Psychiatry, 2001, 4, 29-34.

Leonard A. Jason, Ph.D., Renée R. Taylor, Ph.D., Cara L. Kennedy, B.A.
Sharon Song, M.A., Danielle Johnson, B.A., Susan Torres, M.A.

DePaul University

Abstract
Background:  Pursuit of explanation for prior inconsistent physiological and
psychological findings among individuals with CFS has led researchers to
examine heterogeneity among patient samples that may result from the presence of
comorbid illnesses. 
Most studies of Chronic Fatigue Syndrome (CFS) have been
based on patients recruited from primary or tertiary care settings. Patients
from such settings might not be typical of patients in the general population.

Objectives:  The present study was intended to examine differences between
individuals with CFS with respect to comorbid Fibromyalgia and psychiatric
illness.

Participants and Research Design:  The present investigation involved examining
individuals with CFS from a community-based study.  A random sample of 18,675
respondents in Chicago was first interviewed by telephone. A group of
individuals with chronic fatigue accompanied by at least four minor symptoms
associated with CFS were given medical and psychiatric examinations. From this
sample, a physician review group diagnosed individuals with CFS.  Those
diagnosed with CFS were subclassified based on a variety of categories,
including comorbidity with Fibromyalgia and comorbidity with premorbid,
lifetime, and current psychiatric diagnoses.

Results:  Important differences emerged on measures of sociodemographics,
symptoms, functional disability, stress, and coping.  Individuals with CFS and
comorbid Fibromyalgia demonstrated more symptom severity and functional
impairment than individuals with CFS alone. Individuals with CFS and current or
lifetime psychiatric diagnoses demonstrated greater fatigue and functional
limitations.

Conclusions:  Discrepancies among CFS research findings may be, in part,
attributed to comorbidity with other medical and psychiatric illness.