Despite the availability of empirically supported treatments (ESTs) for posttraumatic stress disorder (PTSD), relatively little is known regarding these treatments' mechanisms of change. This systematic review moves beyond previous reviews by summarizing the findings and reviewing the methodological quality of literature that specifically examined mediators/mechanisms of change in ESTs for PTSD. Studies were included if they were written in English, empirical, peer-reviewed, claimed to study mediators/mechanisms of a recommended PTSD treatment, measured the mediator/mechanism during or before and after treatment, and included a posttreatment PTSD or global outcome (e.g., functioning). PsycINFO and PubMed were searched on October 7, 2022. Two coders screened and coded studies. Sixty-two eligible studies were identified. The most consistent mediator/mechanism was reduction in negative posttraumatic cognitions, followed by between-session extinction and decreased depression. Only 47% of studies measured the mediator/mechanism before the outcome and measured the mediator/mechanism and outcome at least three times, and 32% also used growth curve modeling to establish temporal precedence of change in the mediator/mechanism and outcome. Many of the mediators/mechanisms examined had weak or no empirical support. Results highlight the need for improved methodological rigor in treatment mediator and mechanism research. Implications for clinical care and research are discussed. PROSPERO ID: 248088.

尽管有针对创伤后应激障碍的经验支持治疗（EST）（创伤后应激障碍（PTSD）），人们对这些治疗的变化机制知之甚少。本系统综述超越了之前的综述，总结了研究结果并回顾了专门研究 PTSD EST 变化的中介因素/机制的文献的方法学质量。如果研究以英语撰写、实证、经过同行评审、声称研究推荐的 PTSD 治疗的中介/机制、在治疗期间或治疗前后测量中介/机制、并包括治疗后 PTSD 或总体结果（例如，运行）。PsycINFO 和 PubMed 于 2022 年 10 月 7 日检索。两名编码员对研究进行筛选和编码。确定了 62 项合格的研究。最一致的中介/机制是负面创伤后认知的减少，其次是会话之间的消退和抑郁症的减少。只有 47% 的研究在结果之前测量中介/机制，并测量中介/机制和结果至少三次，32% 的研究还使用生长曲线模型来建立中介/机制和结果变化的时间优先顺序。许多被检查的中介/机制的实证支持很弱或没有。结果强调需要提高治疗中介和机制研究方法的严谨性。讨论了对临床护理和研究的影响。普洛斯彼罗 ID：248088。32% 还使用增长曲线模型来确定中介/机制和结果变化的时间优先级。许多被检查的中介/机制的实证支持很弱或没有。结果强调需要提高治疗中介和机制研究方法的严谨性。讨论了对临床护理和研究的影响。普洛斯彼罗 ID：248088。32% 还使用增长曲线模型来确定中介/机制和结果变化的时间优先级。许多被检查的中介/机制的实证支持很弱或没有。结果强调需要提高治疗中介和机制研究方法的严谨性。讨论了对临床护理和研究的影响。普洛斯彼罗 ID：248088。