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Fall 2001

Characteristics of Long-Duration CFS

By Fred Friedberg, PhD,
State University of New York

Patients ill with chronic fatigue syndrome (CFS) for more than 10 years have only recently been studied. It is important to characterize this long-duration group because they may have distinct features that shed new light on the pathophysiology or genesis of the illness.

This article is based on a multifaceted study of long-term CFS patients that I conducted with Lucy Dechene, PhD, Maggie McKenzie, MA and Robert Fontanetta, BA.^1,2 We compared patient groups with long-duration (median 18 years; n=298) and short-duration (median 3 years; n=28) CFS to a group of healthy significant others (mostly husbands and wives of the patients) (n=179) on symptomatic, neurocognitive and psychological variables.

Illness patterns and severity
An analysis of illness progression in long-duration study participants revealed no typical pattern. Of the approximately two-thirds of patients with a relapsing/remitting disease pattern, some were improving, some were worsening and the rest reported a roughly constant illness over time. The prevalence of specific CFS symptoms (see Table 1) in the long-duration group was similar to that found in other research samples.³ However, compared with the short-duration CFS group, the long-duration group had significantly higher symptom severity scores, largely attributable to increased cognitive difficulties (see Table 2).

In addition to greater cognitive difficulties, long-duration patients also reported significantly higher frequencies of fibromyalgia (FM) and depression compared to the short-duration patients, which may further increase their impairment (see Table 3). Most of the long-duration patients (83.3%) were not working due to their illness, but a slight majority of those with a short duration of illness (51.5%) were. Most long-duration patients experienced onset at a younger age than the short-duration group (28.1 years vs. 42.2 years) and reported a higher percentage of infection with viral illnesses, including infectious mononucleosis (48.9% vs. 39.3%) and human herpesvirus I and II (39.3% vs. 32.1%).

Worsening vs. improving subgroups
We found two well-defined subgroups within the long-duration patient population - those patients who were worsening (n=128) and those who were improving (n=70). These groups were well differentiated on measures of symptom severity, stress, depression and functional status. 

The worsening subgroup was more likely to report the co-morbid conditions of FM (79.8% vs. 62.7%), chronic sinus infections (64.6% vs. 34.2%), thyroid problems (41.4% vs. 27.5%) and asthma (32.8% vs. 17.4%), as well as previous suicide attempts (17.3% vs. 7.3%).  This group also showed significantly elevated levels of stress compared to the improving group.

One surprising finding was that the improving group reported significantly greater symptom severity during the first year of their illness compared to the worsening group. A similar pattern following illness onset was found in the short-term group.

Clinical considerations
Individuals in both the short and long-duration groups rated 29 treatments, but no single treatment emerged as effective for the majority of patients. The highest-rated treatments for both groups combined included anti-allergy diets (32%), antidepressant medications (28%), anti-yeast diets (27%), stress reduction/biofeedback (26%), intravenous vitamins (26%) and physical therapy/massage (26%).

Of these treatments, two were reported to have negative side effects for greater than 10 percent of the respondents - antidepressant medications (31%) and physical therapy/massage (16%). The side effects from physical therapy were most likely pain and relapse following physical exertion. Clinicians can reduce the risk of these side effects by recommending a slow, gradual program that allows adequate time for recovery between sessions.
Our study suggests that long-duration patients report greater cognitive difficulties than short-term patients and are more likely to be unable to work. Clinicians should therefore develop long-term strategies to improve daily functioning in this group of patients. Given the finding of high levels of stress in long-duration patients, stress reduction/relaxation techniques may also be beneficial.

(Editor's Note: The short-term patients were not deemed recovered from CFS at the time the study was conducted; it is likely that many of them will remain ill and eventually become long-duration patients themselves.)

References

1. Friedberg F et al. Symptom patterns in long-duration chronic fatigue syndrome. J Psychosom Res. 2000; 48: 59-68.
2. McKenzie M et al. Cognitive-behavioral coping skills in long-term chronic fatigue syndrome. J CFS. 1995; 1: 59-67.
3. Komaroff A et al. An examination of the working case definition of CFS. Am J Med. 1996; 100: 56-64.

Dr. Fred Friedberg is clinical assistant professor of psychiatry at the State University of New York at Stony Brook. He has authored three books and many articles on CFS and fibromyalgia.