Aetiology of fatigue in Sri Lanka and its overlap with depression.

ABSTRACT

BACKGROUND: Fatigue is a common symptom in Western high-income countries but is often medically unexplained and little is known about its presentation in other populations. AIMS: To explore the epidemiology and aetiology of fatigue in Sri Lanka, and of its overlap with depression. METHOD: A total of 4024 randomly selected twins from a population-based register in Sri Lanka (Colombo district) completed home interviews including the Chalder Fatigue Questionnaire. RESULTS: The prevalence of fatigue was similar to that in other countries, although prolonged fatigue may be less common. There was substantial comorbidity with a screen for lifetime depression. Non-shared environmental factors made the largest contributions, although genetic/family factors also contributed. The aetiology appeared consistent across the spectrum of severity. CONCLUSIONS: The aetiology of fatigue is broadly similar in Sri Lanka and Western high-income countries. Abnormal experiences of fatigue appear to be the extreme form of more common fatigue, rather than representing independent entities with different genetic or environmental risk factors.