Salivary cortisol levels before and after water bath exposure. Stressed participants, independent of genotype for each of the three FKBP5 SNPs (a, b, c), exhibited significant increases in salivary cortisol levels, relative to control (i.e., non-stressed) participants. Stressed risk allele carriers for each polymorphism exhibited greater salivary cortisol levels, overall, than all other groups. Data are expressed as means ± SEM. * P < 0.001 relative to no stress.