Finally, in the analysis of the interaction between genotype and number of life events on risk of depression, the regression coefficient was not significant for females in any of the studies and was nominally significant for males in 2 of the 10 studies.16,27 The meta-analysis showed no interaction effect for either females (OR, 0.95; 95% CI, 0.86-1.04), males (OR, 1.02; 95% CI, 0.86-1.20), or both sexes combined (OR, 0.98; 95% CI, 0.90-1.07). Thus, there was no evidence that the serotonin transporter genotype alone or in interaction with stressful life events is associated with an elevated risk of depression in males alone, females alone, or both sexes combined. The only significant finding across studies was the potent association of stressful life events with the risk of depression.
