Medical: Provider Information

Contrasting Chronic Fatigue Syndrome (CFS) And Major Depressive Disorder (MDD)

ONSET: CFS onset in a significant number of people is acute, coming on suddenly with symptoms described as flu-like. The onset of MDD generally presents with a more gradual onset (Jason et al, 1997). Many CFS patients do not have a history of MDD although some experience depression, a common co-morbidity in individuals with chronic illness (Jason et al, 1997).

INCIDENCE : Clusters or local outbreaks of CFS have been reported, but these are not characteristic of MDD incidence (Farrar et al, 1995).

MAJOR SYMPTOMS : MDD is frequently characterized by a sense of hopelessness, helplessness and feelings of excessive guilt and self-criticism. These are not primary symptoms expressed by people with CFS. MDD and CFS share common, distinct features, such as fatigue, memory problems and sleep disturbances; however, MDD patients do not generally experience most of the physical and neurological deficits seen in people with CFS, which can include: sore throat; tender and/or swollen lymph nodes; unusual headaches; muscle and joint pain; muscle twitching and fatigue; nausea; irritable bowel syndrome; unusual sensitivities to medications; post-exertional malaise; visual and auditory disturbances; speech and language deficits; altered spatial perception; clumsiness and coordination problems; disequilibrium; autonomic disturbances such as neurally mediated hypotension; thermoregulation and others (Shepherd, 1999).

ATTRIBUTIONS : Depressed persons often experience a loss of interest, loss of pleasure (anhedonia) and feelings of worthlessness (Jason et al, 1997). As noted above, MDD is characterized by a sense of hopelessness and helplessness, along with feelings of excessive guilt and self-criticism. The person with CFS lacks these core symptoms of depression (unless they have become clinically depressed after the onset of CFS), particularly anhedonia (Shepherd, 1999).

FATIGUE : Severe, debilitating fatigue is a prominent symptom of CFS, but is named by MDD patients at a much lower incidence, 100% vs. 28%, respectively (Jason et al, 1997).

SLEEP DISORDERS : Sleep problems are common to both CFS and MDD patients, and there may be differing origins for each illness, but data is inconclusive.   Other studies related to neuroendocrine and immunological dysfunction may also lead to the discovery of causes of sleep disruption in CFS (Demitrack, 1996; also see Whiteside, 1998). Furthermore, Shepherd (1999) notes that the associated pain, involuntary leg movements, muscle spasms, night sweats and other symptoms experienced by many CFS patients can negatively impact sleep quantity/quality.

POSTEXERTIONAL MALAISE : Post-exertional exacerbation of symptoms is a hallmark feature of CFS.It can follow either physical or mental stress and generate a relapse significant enough to require complete bedrest and totally incapacitating the individual. Some studies have shown that this condition is present at a rate of 79-87% in CFS and 19% in MDD (Jason et al, 1997).

EXERCISE INTOLERANCE : Exercise intolerance is characteristic of CFS, but not MDD. CFS symptoms often worsen with exercise, while MDD symptoms generally show improvement (Shepherd, 1999).

COGNITIVE : Jason et al. (1997) state that CFS patients have slow decision-making speed, and have more difficulty than controls sustaining attention to figural and verbal stimuli. Depressed patients have more trouble with figures than verbal stimuli, while CFS patients are equally impaired in both areas. Other studies, cited by Jason et al. (1997), indicate that paired-associate learning was much worse in CFS than in MDD and memory impairment differences appear to be associated with attention deficits in the CFS patient rather than with memory storage problems.

PSYCHOLOGICAL : Various psychiatric scoring instruments can beutilized to differentiate CFS and MDD. Findings in several studies (Jason et al, 1997) suggest that “high or low psychiatric rates in CFS samples may be a function of whether symptoms are attributed to psychiatric or nonpsychiatric causation.”In Johnson et al. (1996), when CFS case definition symptoms that overlap with psychiatric diagnoses were coded as physical, the prevalence of psychiatric diagnoses decreased 78%.

NEUROENDOCRINE : Frequently replicated research findings indicate abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis. In MDD, levels of plasma cortisol are elevated and there is an exaggerated response to corticotropin (ACTH). In CFS, plasma cortisol levels are low and there is a reduced response to ACTH. Additional research has encompassed investigation into the role of serotonin receptors, serum prolactin and melatonin secretion. In several studies, differences in these factors have been noted between CFS and MDD, but findings are inconclusive (Farrar et al, 1995).

PATIENT HISTORY : Most of the recent research has found that depression in CFS is a secondary reaction to the chronic illness, and is similar to the depression seen in other debilitating chronic illnesses such as multiple sclerosis or Parkinson's disease. Studies have shown that depression in CFS usually follows onset and most CFS patients do not experience depression prior to becoming ill (Jason et al, 1999).

COURSE OF ILLNESS : CFS can exist for many years, but it is not a progressive disease. Symptoms can wax and wane for the duration of the illness. Many people do recover, (Saunders, 1998); however, full recovery is rare. Data on CFS prognosis is limited.

RESPONSES TO TREATMENT : Cognitive-behavioral therapy has been shown to be helpful for both groups; however, it has not improved the fatigue of CFS (Jason et al, 1997). Non-psychotropic drugs including antivirals, immune modifiers and ion flow treatments (Jorge & Goodnick, 1997) have been used in CFS therapy but responses to these are varied and could be termed investigational since few double-blind and random studies have been done In addition, many CFS patients with co-morbid depression do not tolerate standard doses of antidepressant medications; symptom improvement may be noted at lower dosages than the [proven] effective dosages prescribed for the MDD patient (Jorge & Goodnick, 1997; Shepherd, 1999).

References

1. Demitrack, M. (1997). Neuroendocrine correlates of chronic fatigue syndrome: A brief review. Journal of Psychiatric Research, 31 (1), 69-82.
2. Farrar, D., Locke, S., Kantrowitz, F. (1995, Spring). Chronic fatigue syndrome 1: Etiology and pathogenesis. Behavioral Medicine, 21, 5-24.
3. Fukuda, K., & Gantz, N. (1995, July). Management strategies for chronic fatigue syndrome. Federal Practitioner. Belle Mead, NJ: Excerpta Medica: Reed Elsevier Medical Publishing.
4. Jason, L., Richman, J., Friedberg, F., Wagner, L., Taylor, R., Jordan, K. (1997, September). Politics, science, and the emergence of a new disease. American Psychologist, 52 (9), 973-984.
5. Jason, L., Richman, J., Rademaker, A., Jordan, K., Plioplys, A., Taylor, R.,
6. McCready, W., Huang, C., Plioplys, S. (1999, October 11). A community-based study of chronic fatigue syndrome. Archives of Internal Medicine, 159, 2129-2137.
7. Johnson, S.K., DeLuca, J., Natelson, B.J. Assessing somatization disorder in the chronic fatigue syndrome. Psychosomatic Medicine, 58, 50-57.
8. Jorge, C., & Goodnick, P. (1997, May). Chronic fatigue syndrome and depression: Biological differentiation and treatment. Psychiatric Annals 27:5, 365-371.
9. Saunders, C. (1998, September 15). New directions in chronic fatigue syndrome. Patient Care, 32 (14), 101-110.
10. Shepherd, C. (1999). Living with M.E.: The Chronic / Post-Viral Fatigue Syndrome (Rev. ed., pp.72-75, 154-56, 182, 231-32). London : Random House.
11. Whiteside, T. & Friberg, D. (1998, September 28). Natural killer cells and natural killer cell activity in chronic fatigue syndrome. The American Journal of Medicine, 105 (3A), 17S-34S. Excerpta Medica.