Preliminary evidence: the stress-reducing effect of listening to water sounds depends on somatic complaints: A randomized trial.

BACKGROUND: Listening to natural sounds is applied in health contexts in order to induce relaxation. However, it remains unclear whether this effect is equally efficacious in all individuals or whether it depends on interindividual differences. Given that individuals differ in how they are impaired by somatic complaints, we investigated whether somatic complaints moderate the stress-reducing effect of listening to water sounds. METHODS: Sixty healthy women (Mage = 25 years) were randomly allocated to 3 different conditions (listening to water sounds, a relaxing piece of music, or no auditory stimulus: n = 20 per condition) for 10 minutes before they were exposed to a standardized psychosocial stress task. Salivary cortisol was assessed before, during, and after the stress task. For binary logistic regression analyses, participants were divided into 2 groups: 1 group with a high salivary cortisol release and 1 group with low cortisol release. The Freiburg Complaints Inventory was used to assess occurrence of somatic complaints. RESULTS: A significant moderating effect of somatic complaints on cortisol secretion was found in the group listening to water sounds (χ(1) = 5.87, P < .015) but not in the other 2 groups, explaining 35.7% of the variance and correctly classifying 78.9% of the cases. CONCLUSION: The stress-reducing effect of listening to water sounds appears to depend on the occurrence of somatic complaints. This effect was not found in the music or silence condition. Individuals with somatic complaints may benefit from other, potentially more powerful forms of stress-reducing interventions, that is, combinations of visual and auditory stimuli. TRIAL REGISTRATION: not applicable (pilot study).

Altered salivary alpha-amylase awakening response in Bosnian War refugees with posttraumatic stress disorder.

In posttraumatic stress disorder (PTSD), chronic activation of the sympathetic nervous system (SNS) has been suggested. No study so far has investigated diurnal secretion patterns of salivary alpha-amylase (sAA) in PTSD, a promising candidate for non-invasive assessment of SNS activity. We compared sAA diurnal profiles between a group of Bosnian War refugees with PTSD and a healthy control group, and further analyzed for associations with psychiatric symptoms and glucocorticoid (GC) sensitivity of inflammatory regulation. PTSD patients showed a sAA awakening response profile that was opposite to those seen in healthy controls, i.e. an increase instead of a sharp decrease. Patterns of sAA secretion were further positively associated with psychiatric symptoms of PTSD. Finally, higher sAA awakening responses were associated with higher GC sensitivity of inflammatory cytokine production. These findings are in line with altered SNS function in PTSD, and lend further support for employing assessment of diurnal sAA profiles as non-invasive biomarkers in stress-related disease.