Genetic and environmental contributions to depression in Sri Lanka
H. A Ball,
S. H Siribaddana,
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.
To examine heritability of depression in the first large, population-based
twin study in a low-income country.
Lifetime depression and a broader measure of depression susceptibility
(D-probe) were assessed in 3908 adult twins in Sri Lanka (the CoTASS
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.
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.