Supplementary Material for: Effectiveness of an Internet-Based Self-Help Intervention versus Public Mental Health Advice to Reduce Worry during the COVID-19 Pandemic: A Pragmatic, Parallel-Group, Randomized Controlled Trial

Introduction: The mental health burden for the general population due to the COVID-19 pandemic has been highlighted. Evidence on effective, easily accessible public health interventions to reduce worry, a major transdiagnostic risk-factor for, e.g., anxiety and depression, is scarce. Objective: In a pragmatic randomized controlled trial, we aimed to assess whether an internet cognitive-behavioral self-help intervention could reduce worry more than public mental health advice in the general population. Methods: Eligible internet users above the age of 18 were recruited from the German general population and randomly assigned, to either get.calm-move.on (GCMO), a 10-day unguided, internet-based self-help intervention, or mental health advice waiting group (MHA-W, receiving officially endorsed mental health recommendations). The primary outcome was level of worry, using the Penn State Worry Questionnaire (PSWQ), 2 weeks after randomization. Baseline assessment and 2-month and 6-month follow-ups were conducted. The trial was registered at the German Clinical Trials Registry (DRKS00021153). Results: Between April 7, 2020 and December 11, 2020, we randomly assigned 351 individuals to receive either GCMO (n = 175) or MHA-W (n = 176). Participants receiving GCMO (PSWQ = 46.6; change –10.3) reported significantly less worrying at post-intervention (F1,219 = 12.9; p < 0.001; d = 0.38) than MHA-W controls (PSWQ = 51.6; change –5.1). Improvements were also seen on most secondary outcomes, including symptoms of anxiety and depression, general well-being, resiliency, and emotion regulation skills. Improvements made from baseline were stable until the 6-month follow-up. Conclusions: This internet-based self-help intervention providing cognitive-behavioral techniques to cope with the threatening pandemic situation is effective in reducing worry in the general population and should complement existing and potentially effective mental health recommendations.

引言：新冠疫情给普通人群带来的心理健康负担已受到广泛关注。担忧是焦虑、抑郁等多种精神障碍的重要跨诊断危险因素，而目前关于可有效缓解担忧、且易于获取的公共卫生干预措施的相关研究证据仍较为匮乏。
研究目的：本研究采用实用性随机对照试验设计，旨在评估相较于官方公共心理健康指导方案，基于互联网的认知行为自助干预措施能否更有效地缓解普通人群的担忧情绪。
研究方法：本研究从德国普通人群中招募符合入组条件的18岁以上互联网用户，将其随机分为两组：一组接受为期10天的非指导式互联网认知行为自助干预项目get.calm-move.on（GCMO），另一组为心理健康指导等候组（MHA-W，将获得官方认可的心理健康建议）。本研究的主要结局指标为随机分组后2周时采用宾夕法尼亚洲担忧问卷（Penn State Worry Questionnaire, PSWQ）评估的担忧水平。研究采集了基线评估数据，并分别在分组后2个月、6个月进行了随访。本试验已在德国临床试验注册平台（German Clinical Trials Registry, DRKS00021153）完成注册。
研究结果：2020年4月7日至2020年12月11日期间，本研究共纳入351名受试者，随机分为GCMO组（n=175）与MHA-W对照组（n=176）。干预后评估结果显示，GCMO组受试者的担忧水平（PSWQ得分46.6，较基线降低10.3分）显著低于MHA-W对照组（PSWQ得分51.6，较基线降低5.1分），组间差异具有统计学意义（F₁,₂₁₉=12.9；p<0.001；d=0.38）。多数次要结局指标也呈现出显著改善，包括焦虑与抑郁症状、总体幸福感、心理弹性及情绪调节能力。从基线至6个月随访期内，受试者的症状改善情况保持稳定。
研究结论：本研究表明，这款针对新冠疫情威胁情境、融入认知行为应对策略的互联网自助干预措施，可有效缓解普通人群的担忧情绪，可作为现有潜在有效心理健康指导方案的有益补充。