Well-being and ill-being: shared environments, shared genes?

Abstract

The nature of the associations between life satisfaction, anxiety, and depression remains elusive. Using questionnaire data from a large population-based sample (N = 6326) of young adult Norwegian twins (aged 18–31 years) we explored the extent to which latent genetic and environmental factors are (1) common or distinct, and (2) sex-specific. Phenotypic correlations ranged between 0.44 and 0.70 in females, and between 0.41 and 0.69 in males. Environmental influences accounted for 75% of these correlations in females, and less than 50% in males. Genetic and environmental sources of life satisfaction, symptoms of anxiety, and symptoms of depression were shared mostly, but the magnitude of the effects was different in males and females. In both sexes, however, aetiological factors enhancing life satisfaction were simultaneously protecting against feelings of sadness and displeasure, but contributed less to countervailing anxiety and tension.

Keywords:

• life satisfaction
• subjective well-being
• psychological distress
• anxiety
• depression
• heritability
• twins

Acknowledgements

The twin program of research at the Norwegian Institute of Public Health is supported by grants from The Norwegian Research Council, The Norwegian Foundation for Health and Rehabilitation, and by the European Commission under the programme ‘Quality of Life and Management of the Living Resources’ of 5th Framework Programme (no. QLG2-CT-2002-01254). We are very thankful to the twins for their participation. The work reported here was funded fully from grants and agencies as listed above. There are no conflicts of interests for the authors related to the content of this manuscript and any source of financial interest or organizational affiliation.