SLC6A4 and depressive symptom measurement: Post-hoc analyses of this replication finding revealed that while stressful life events were a risk factor for depression for both sexes, the role of the 5HTTLPR and its interaction with stressful life events approached significance (p = 0.007, 95% CI: -0.54 to -0.09) only for males [Fig 1a and 1b, Table 1].