Genetic and environmental contributions to the overlap between psychological, fatigue and somatic symptoms: a twin study in Sri Lanka

Harriet A Ball, Sisira H Siribaddana, Athula Sumathipala, Yulia Kovas, Nick Glozier, Frühling Rijsdijk, Peter McGuffin, Matthew Hotopf

Research output: Contribution to journalArticle (Academic Journal)peer-review

17 Citations (Scopus)


BACKGROUND: Somatic symptoms often co-occur with psychological symptoms but this overlap is poorly understood. Some aspects of this overlap differ in the South Asian context, but it is not clear whether this is a reporting effect or an underlying difference in experienced illness.

METHODS: Home interviews were administered to 4,024 twins randomly selected from a population-based twin register in the Colombo district of Sri Lanka (the CoTASS study). These included assessments of psychological, somatic and fatigue symptoms. The data were analyzed using factor analytic and quantitative genetic approaches.

RESULTS: Confirmatory factor analysis showed that the symptoms from the three scales represented three separate dimensions, rather than all tapping into a single dimension. However, familial correlations among the data were most consistent with a common pathway model. This implies that a portion of the underlying vulnerability is common across psychological, fatigue and somatic symptoms. There were sex differences in the etiology of this model, with shared environmental and genetic influences playing different roles in men and women.

CONCLUSIONS: There is a complex etiological relationship between psychological, fatigue and somatic symptoms. This is similar in Sri Lanka to Western countries, but there may be a greater influence from the family environment, suggesting that care needs to be taken when generalizing research findings between countries. People who complain of certain fatigue or somatic symptoms may well also have psychological symptoms, or may have genetic or environmental vulnerabilities to such problems.

Original languageEnglish
Pages (from-to)53-63
Number of pages11
JournalTwin Research and Human Genetics
Issue number1
Publication statusPublished - Feb 2011


  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Diseases in Twins/diagnosis
  • Fatigue/diagnosis
  • Female
  • Humans
  • Male
  • Middle Aged
  • Models, Genetic
  • Phenotype
  • Risk Factors
  • Sex Factors
  • Socioeconomic Factors
  • Sri Lanka/epidemiology
  • Surveys and Questionnaires
  • Twins, Dizygotic/genetics
  • Twins, Monozygotic/genetics
  • Young Adult


Dive into the research topics of 'Genetic and environmental contributions to the overlap between psychological, fatigue and somatic symptoms: a twin study in Sri Lanka'. Together they form a unique fingerprint.

Cite this