Genetic and population perspectives on life events and depression.

Population comparisons of epidemiological surveys using the same investigator-based measures suggest that large differences are possible in the experience of clinically relevant depression and of life events capable of provoking such episodes. It is argued that, given the great majority of onsets in the various populations were provoked by a life event, the differences in the experience of depression are likely to have been largely the result of psychosocial factors. Moreover, this interpretation would still be likely to hold even if heritability (h2) coefficients for depression within the component populations were substantial. The same argument would hold for the interpretation of the across-population differences in the experience of life events. New material concerning the differing experience across populations of humiliation/entrapment events, known to be particularly depressogenic, is also presented and the implications of the findings for future aetiological research discussed.