Next we tested whether the depressive effect of 5-HTTLPR is mediated by the increased BSI anxiety scores related to the increasing number of s alleles. When we used BSI anxiety as a covariate in the regression models the significant 5-HTTLPRxRLE interaction on lifetime depression and BSI depression scores became a trend in the total population (Table 2). Involving BSI anxiety, 5-HTTLPRxRLE trend on lifetime depression also disappeared in the young subpopulation (Table 2). These results suggest that BSI anxiety partially mediates the depressive effect of 5-HTTLPRxRLE interaction, especially in young people.
