Abstract
•Evening cortisol levels assessed at baseline were higher than the levels in healthy individuals•The morning cortisol levels showed a statistically significant increase by the end of the CBTp intervention, as participants presented with very low levels initially•Statistically significant clinical improvement was observed at the end of the 16 weekly CBTp sessions, by comparison to the control group•Several baseline variables were identified as correlating significantly with the main outcome measures of the CBTp intervention, including the evening cortisol level.