BACKGROUND: Susceptibility to depression results from genetic and non-familially shared environmental influences in high-income, Western countries. Environments may play a different role for populations in different contexts.
AIMS: To examine heritability of depression in the first large, population-based twin study in a low-income country.
METHOD: Lifetime depression and a broader measure of depression susceptibility (D-probe) were assessed in 3908 adult twins in Sri Lanka (the CoTASS study).
RESULTS: There were gender differences for the broad definition (D-probe), with a higher genetic contribution in females (61%) than males (4%). Results were similar for depression, but the prevalence was too low to estimate heritability for males.
CONCLUSIONS: Genetic influences on depression in women appear to be at least as strong in this Sri Lankan sample as in higher-income countries. Conclusions are less clear for men but suggest a larger role for environments rather than genes. The nature as well as the magnitude of environmental influences may also differ across populations.
- Age Factors
- Analysis of Variance
- Depressive Disorder/epidemiology
- Diseases in Twins/genetics
- Middle Aged
- Psychiatric Status Rating Scales
- Sex Factors
- Social Environment
- Sri Lanka/epidemiology
- Young Adult