中華心理衛生協會

Purpose: We examined how Lifeline, a suicide prevention hotline in Taiwan, achieves therapeutic outcomes. Previous research has measured verbal synchrony using the similarity in the proportion of function words used by 2 people, referred to as Language Style Matching (LSM). The LSM index can be calculated using different methods, including static LSM and dynamic reciprocal LSM (rLSM), both of which are considered indices of therapeutic alliance-a crucial factor in promoting therapeutic effectiveness. Although suicide hotlines are known to be effective, their underlying mechanisms remain unclear. Therefore, we investigated whether higher LSM or LSM between trained Lifeline volunteers and callers facilitates perspective changes and reduces callers' psychological distress. Method: We analyzed 754 verbatim transcripts of conversations between Lifeline volunteers and first-time callers. We identified linguistic markers for LSM, rLSM, perspective changes, and psychological distress using LIWC software. We used mediation analyses to address the research questions. Results: After controlling for gender, baseline psychological distress, and suicide risk levels, the mediation analysis revealed that static LSM increased psychological distress by reducing the likelihood of perspective changes in callers. In contrast, rLSM decreased psychological distress by facilitating perspective changes in callers. Conclusion: Static LSM may reinforce the caller's existing negative psychological state, leading to a more rigid perspective and hindering the reduction of psychological distress in the context of Lifeline. In contrast, higher rLSM reflects that the volunteers continuously adapted their language style to match their callers, fostering a therapeutic alliance, encouraging perspective changes, and reducing psychological distress. These findings provide insight into the underlying mechanism through which suicide prevention hotlines achieve their therapeutic effectiveness.