Table 2.

Studies on HPA axis alteration.

Reference	Sample	Psychological Assessment	Materials and Procedures	Main Findings
Epel, 1998 [38]	A cohort of women exposed to stress	PTGI -	total cortisol response each day and adaptation across days	Women who quickly adapted to the repeated laboratory stressors were more likely to report thriving in response to previous traumatic stress
Cruess, 2000 [35]	34 stage 1 or 2 breast cancer patients enrolled 8 weeks after surgery	CBS therapy; BFS; POMFS	Cortisol levels measured in serum through radioimmunoassay	Participants with PTSD who underwent CBS therapy demonstrated lower levels of cortisol and higher levels of cognitive-behavioral stress management
Smyth, 2008 [36]	25 PTSD patients	PSS-I; PTGI	Salivary cortisol level measured at the arrival, before imagery-based trauma re-experience, after the re-living of the experience	Subjects with higher PTGI scores, also had lower salivary cortisol levels, suggesting an inverse correlation between the two
Diaz, 2014 [37]	99 patients with breast cancer	PTGI	Cortisol slope at waking up in morning, noon and at 5 and 9 p.m for two consecutive day	PTGI scores were inversely proportional to diurnal cortisol.

CBS: Cognitive Behavioral Strategies; BFS; Benefit Findings Scale; POMFS; Profile of mood State Scales; PSS-I: PTSD symptoms interview; PTGI: Post-traumatic Growth inventory.