A randomized waitlist-controlled trial comparing detached mindfulness and cognitive restructuring in obsessive-compulsive disorder

Objective
Whereas research has demonstrated the efficacy of cognitive restructuring (CR) for obsessive-compulsive disorder (OCD), little is known about the efficacy of specific metacognitive interventions such as detached mindfulness (DM). Therefore, this study compared the efficacy of CR and DM as stand-alone interventions.
Design
We conducted a randomized waitlist-controlled trial. n = 43 participants were randomly assigned to either DM or CR. Out of those participants, n = 21 participants had been previously assigned to a two-week waitlist condition.
Materials and methods
In both conditions, treatment comprised four double sessions within two weeks. Assessment took place at baseline (Pre1), after treatment (Post) and four weeks after the end of treatment (FU). There was a second baseline assessment (Pre2) in the waitlist group. Independent evaluators were blinded concerning the active condition. Adherence and competence ratings for the two therapists were obtained from an independent rater.
Results
40 patients completed the treatment. Two patients dropped out because of exacerbated depression. There were no further adverse events. Both CR and DM were shown to be superior to waitlist and equally effective at reducing OCD symptoms from pre to post assessment as measured with the Y-BOCS (CR: d = 1.67, DM: d = 1.55). In each of the two treatment conditions, eight patients (40%) exhibited a clinical significant change at post assessment.
Conclusions
The results of this clinical trial suggest the potential efficacy of DM as a stand-alone intervention for OCD, however, our findings need to be interpreted with caution. Results indicate that both CR and DM should be considered as possible alternative treatments for OCD, whereas the working mechanisms of DM have yet to be elucidated.

研究目标
已有研究证实认知重构（cognitive restructuring, CR）对强迫症（obsessive-compulsive disorder, OCD）具有确切疗效，但针对分离式正念（detached mindfulness, DM）这类特定元认知干预手段的疗效，目前尚无充分研究证据支撑。因此本研究旨在比较作为单一干预手段的CR与DM的临床疗效。

试验设计
本研究采用随机等待列表对照试验设计。共计43名参与者被随机分配至DM组或CR组，其中21名参与者此前已被纳入为期两周的等待列表对照组。

材料与方法
两组干预均在两周内完成四次时长加倍的治疗时段。评估节点设置为：基线评估（Pre1）、治疗结束即刻（Post）以及治疗结束后四周的随访阶段（FU）；等待列表组额外增设第二次基线评估（Pre2）。独立评估员对受试者所属的干预分组设盲，以规避评估偏倚。由独立评分员对两名治疗师的干预依从性与治疗胜任力进行评分。

研究结果
共计40名患者完成全部干预流程。2名患者因抑郁症状加重退出试验，未出现其他不良事件。结果显示，CR与DM均优于等待列表对照组，且以耶鲁-布朗强迫症量表（Yale-Brown Obsessive Compulsive Scale, Y-BOCS）评分变化为衡量标准时，两组在治疗前后的强迫症症状改善效果相当（CR：d=1.67，DM：d=1.55）。在两个干预组中，各有8名患者（占比40%）在治疗后评估中表现出具有临床显著性的症状改善。

研究结论
本临床试验结果表明，DM作为单一干预手段用于治疗强迫症具有潜在疗效，但本研究发现仍需谨慎解读。研究结果提示，CR与DM均可作为强迫症的可选治疗方案，而DM的具体作用机制仍有待进一步阐明。