Perceptions of risk characteristics of earthquakes compared to other hazards and their impact on risk tolerance.

People tolerate different levels of risk owing to a variety of hazards. Previous research shows that the psychometric properties of hazards predict people's tolerance of them. However, this work has not taken into account events such as earthquakes. The present study tested how earthquakes score vis-à-vis risk properties and risk tolerance as compared to five other familiar hazards. Participants from Wellington, New Zealand (N=139) rated these six hazards using measures of risk characteristics and risk tolerance. Participants demonstrated different levels of risk tolerance for the different hazards and viewed earthquakes as having similar risk features to nuclear power. They also preferred different risk mitigation strategies for earthquakes (more government funding) to the other five hazards (stronger legislation). In addition, earthquake risk tolerance was predicted by different risk characteristics than the other five hazards. These findings will help risk communicators in identifying which risk characteristics to target to influence citizens' risk tolerance.

The role of the communicated treatment rationale on treatment outcome: study protocol for a randomized controlled trial.

BACKGROUND: Placebo effects are a well-established phenomenon in the treatment of depression. However, the mechanism underlying these effects are not fully understood. Treatment expectations are considered one explanation for why placebos work. Treatment expectations are likely to be affected by clinician-patient interactions. This study aims to investigate the role of the communicated treatment rationale in modulating treatment expectations and its effects on the treatment outcomes of a pharmacological and a psychological active placebo intervention for depression. In this study, treatment expectations are modulated by presenting illness models that are either congruent or incongruent with the treatment intervention that follows. METHODS: This 2 × 2 randomized controlled trial will involve patients with major depression. Participants will either receive a biological or a psychological illness model from a clinician. Following this, they are randomly assigned to receive either a pharmacological or a psychological active placebo intervention. The illness model and the treatment are either congruent or incongruent with each other, resulting in four groups. In addition, a natural course control group will be included. DISCUSSION: This study will provide insights into the mechanism of expectation modulation in active placebo treatments for major depression. The results may provide insights for clinicians to improve their communication with patients by focusing on treatment expectations. By identifying the factors that contribute to placebo effects, this study has the potential to improve the effectiveness of existing depression treatments and reduce the burden of this highly prevalent mental health condition. TRIAL REGISTRATION: This trial has been registered prospectively at ClinicalTrials.gov under the identifier: NCT04719663. Registered on January 22, 2021.