Can verbal suggestions strengthen the effects of a relaxation intervention?

In this study, we investigated the effects of a brief relaxation intervention on stress-related outcomes and whether verbal suggestions can strengthen the effects. In our randomized controlled study, healthy participants (N = 120) were randomly assigned to 1 of 4 conditions: a brief relaxation intervention plus verbal suggestions condition, a brief relaxation intervention only condition, a verbal suggestions only condition, or a control condition. Afterwards, participants were exposed to a psychosocial stress challenge to assess reactivity to a stressful event. Stress-related outcomes were assessed by incorporating self-report questionnaires, including state anxiety. Furthermore, measures of cortisol and alpha amylase, as well as measures of heart rate and skin conductance were incorporated. Results showed that immediately after both relaxation interventions (with and without the verbal suggestions) participants reported lower self-reported state anxiety. The verbal suggestions did not impact state anxiety. No effects were found for cortisol, alpha amylase, heart rate and skin conductance.