(a and b) Mean (s.e.m.) of percentage change in plasma ACTH in allelic differences in COMT genotype as a function of MAOA during PS, MA, gain, loss and recovery, with the differences between met/met and val/val variants being the most significant only within the low-expression MAOA variants (P<0.05 corrected). (c) Mean (s.e.m.) of percentage change in stress-related cortisol response, showing an interaction between allelic variations of 5-HTT and Sex. Regarding this interaction, the individuals with the SS variant showed increased percentage change in plasma cortisol response to the stressors than those with the LS and LL variants but only in women (P<0.05 corrected). (d) Mean (s.e.m.) of percentage change in plasma cortisol response to PS and MA as a function of individuals' 5-HTT allelic variations, while the LL and LS variants did not differ in their response, both differed significantly from the SS variants during SP, PS and MA (P<0.05 corrected).