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. Author manuscript; available in PMC: 2022 Aug 12.
Published in final edited form as: Neuropsychopharmacology. 2022 Feb 9;47(10):1798–1807. doi: 10.1038/s41386-022-01283-8

Figure 2. Effects of morphine administration on physiological and subjective stress responses.

Figure 2

(A) Morphine administration suppressed the hypothalamic–pituitary–adrenal (HPA) axis activity, as shown by blunted salivary cortisol before and after stress induction. No significant drug effects were observed in the autonomic nervous system (ANS) response to stress, assessed via salivary alpha-amylase (sAA) and heart rate. (B) Morphine administration also increased the subjective negative response to stress, as shown by higher scores on the “Anger” subscale (POMS) and elevated negative mood (VAS) immediately after the Trier Social Stress Test (TSST). No significant drug effects were observed in positive mood or in any other POMS subscales (depression, vigor, fatigue). Grey bars represent the TSST time window (anticipation, speech, and arithmetic task); error bars represent standard error of the mean; asterisks indicate significant differences between drug groups (** p <.01, *** p < .001).