Fatigue is a condition characterised by persistent weakness
or exhaustion and a combination of symptoms that feature
self-reported impairments in some of the following: impaired
attention and concentration, headaches, unrefreshing sleep,
and/or musculoskeletal pain [1]. Fatigue is an experiential
state typically diagnosed on the basis of self-reports and is
a common complaint in the general population [2, 3]. It is
usually associated withmiddle age, being female, and having
lower education and occupation attainment [4]. Fatigue
is common in psychiatric conditions such as anxiety and
depression (25–36%) [5–7] and in chronic medical conditions
such as cancer, Parkinson’s disease, multiple sclerosis,
diabetes, and viral infection [8–12]. Fatigue worsens with
increasing physical disease severity [10] and is independent
of medication suggesting that medication itself is not responsible
for fatigue.