Psychological Factors

Fatigue is a frequent complaint in psychological disorders. Conversely, a long-lasting fatigue can generate emotional problems and be a source of anxiety. In CFS, psychological distress and depression are commonly seen (Katon, 1993). Whether this is a cause or a consequence of chronic fatigue can be debated. In any case, psychological wellbeing should be addressed in the management of CFS since it may exacerbate and/or perpetuate the illness.

Genetic Factors:

Some of the biological and physiological parameters known to be involved in CFS etiology, such as hormonal and immunological functions as well as aerobic capacity, are heritable and a growing number of studies point toward a genetic influence on chronic fatigue. For example, in one study, specific HLA antigens (HLA-DQ3 and HLA-DR5) were found in association with CFS (Keller, 1994). Moreover natural killer cell dysfunction was reported in siblings with CFS (Levine, 1998). A high incidence of auto-antibodies against specific phospholipids and gangliosides is also found in families where CFS runs (Klein, 1995). Globally these findings are interpreted as signs of an inherited predisposition to CFS. A recent twin study estimated the liability of CFS to be around 19% (Buchwald, 2001). Nevertheless, the often CFS-associated psychological distress showed no evidence of genetic covariation (Walsh, 2001).

Figure 1. Potential pathways to chronic fatigue syndrome

Source: "Chronic Fatigue Sydrome, clinical practice guidlines 2002", Health Policy Unit, Royal Australian College of Physicians, Syndney NSW MJA, vol. 176, May 2002