Stressors, coping and symptoms of adjustment disorder in the course of the COVID-19 pandemic–study protocol of the European Society for Traumatic Stress Studies (ESTSS) pan-European study/ COVID-19大流行过程中的应激源、应对方式和适应障碍症状–欧洲创伤应激研究学会（ESTSS）泛欧洲研究的研究方案/ Estresores, afrontamiento y síntomas de trastorno de adaptación en el curso de la pandemia de COVID-19 - protocolo de Estudio de la Sociedad Europea de Estudios de Estres Traumático (ESTSS) estudio pan-europeo

Background: During the current COVID-19 pandemic, the people in Europe are exposed to self-isolation, quarantine, job loss, risk of contracting COVID-19, or grief of loved ones. Such a complex array of stressors may lead to symptoms of adjustment disorder or posttraumatic stress disorder. This research protocol describes a study launched by the European Society of Traumatic Stress Studies (ESTSS) to investigate the impact of the COVID-19 pandemic on symptoms of adjustment disorder across European countries. Objective: The longitudinal online cohort study aims (1) to explore psychosocial reactions to the COVID-19 pandemic across ten European countries; (2) to examine the relationships between risk and resilience factors, stressors and symptoms of adjustment disorder during the pandemic; and (3) to investigate whether these relationships are moderated by coping behaviours. Method: In ten countries (Austria, Croatia, Georgia, Germany, Italy, Lithuania, Netherlands, Poland, Portugal, and Sweden), between 1,000 and 2,000 participants will be recruited, depending on the size of the country. Participants will be assessed at two timepoints with a six-month interval. Following a conceptual framework based on the WHO’s social framework of health, an assessment of risk and resilience factors, COVID-19 related stressors and pandemic-specific coping behaviours will be measured to estimate their contribution to symptoms of adjustment disorder. The Adjustment Disorder New Module 8 (ADNM-8) will be used to assess symptoms of adjustment disorder. As a secondary measure, symptoms of posttraumatic stress disorder will be measure using the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5). Data analysis: The relative contribution of risk factors, resilience factors, and stressors on symptoms of adjustment disorder or symptoms of posttraumatic stress disorder will be estimated using multilevel analysis. To determine the moderating effects of different types of coping behaviours on these relationships, a multilevel mediation analysis will be carried out.