Supplementary Material for: Inference-Based Cognitive Behavioral Therapy versus Cognitive Behavioral Therapy for Obsessive-Compulsive Disorder: A Multisite Randomized Controlled Non-Inferiority Trial

Introduction: Although cognitive behavioral therapy (CBT) effectively treats obsessive-compulsive disorder (OCD), many patients refuse CBT or drop out prematurely, partly because of anxiety regarding exposure and response prevention (ERP) exercises. Inference-based cognitive behavioral therapy (I-CBT) focuses on correcting distorted inferential thinking patterns, enhancing reality-based reasoning, and addressing obsessional doubt by targeting underlying dysfunctional reasoning, without incorporating an ERP component. We hypothesized that I-CBT would be non-inferior to CBT. Additionally, we hypothesized that I-CBT would be more tolerable than CBT.
Methods: 197 participants were randomly assigned to 20 sessions CBT or I-CBT and assessed at baseline, post-treatment, and 6 and 12 months follow-up. The primary outcome was OCD symptom severity measured using the Yale-Brown Obsessive Compulsive Severity Scale (Y-BOCS; non-inferiority margin: 2 points). The secondary outcome, treatment tolerability, was assessed using the Treatment Acceptability/Adherence Scale (TAAS). A linear mixed-effects model was used to assess the non-inferiority of the primary outcome and superiority of secondary outcomes.
Results: Statistically significant within-group improvements in the primary and secondary outcomes were observed in both treatments. No statistically significant between-group differences in Y-BOCS were found at any assessment point, but the confidence intervals exceeded the non-inferiority threshold, making the results inconclusive. The estimated mean post-treatment TAAS score was significantly higher in the I-CBT group than in the CBT group.
Conclusion: While both CBT and I-CBT are effective for OCD, whether I-CBT is non-inferior to CBT in terms of OCD symptom severity remains inconclusive. Nevertheless, I-CBT offers better tolerability and warrants consideration as an alternative treatment for OCD.

引言：尽管认知行为疗法（Cognitive Behavioral Therapy, CBT）可有效治疗强迫症（Obsessive-Compulsive Disorder, OCD），但诸多患者会拒绝接受CBT或过早脱落治疗，部分原因在于其对暴露与反应阻断疗法（Exposure and Response Prevention, ERP）相关练习存在焦虑情绪。基于推理的认知行为疗法（Inference-based Cognitive Behavioral Therapy, I-CBT）通过靶向干预潜在的功能失调性推理过程，致力于纠正扭曲的推理思维模式、强化基于现实的推理能力并缓解强迫性疑虑，且未纳入ERP相关环节。本研究假设I-CBT的疗效不劣于CBT，同时假设I-CBT的治疗耐受性优于CBT。
方法：本研究共纳入197名受试者，将其随机分配至接受20次CBT或I-CBT治疗组，并分别于基线、治疗结束时以及随访6、12个月时进行评估。主要结局指标为采用耶鲁-布朗强迫症严重程度量表（Yale-Brown Obsessive Compulsive Severity Scale, Y-BOCS；非劣效界值：2分）评估的强迫症症状严重程度。次要结局指标为治疗耐受性，采用治疗接受度/依从性量表（Treatment Acceptability/Adherence Scale, TAAS）进行评估。本研究采用线性混合效应模型，对主要结局指标的非劣效性以及次要结局指标的优效性进行检验。
结果：两种治疗方案均在组内观察到主要及次要结局指标的统计学显著改善。各评估时点的Y-BOCS组间差异均无统计学意义，但置信区间超出非劣效界值，导致研究结果无法得出明确结论。I-CBT组治疗结束后的估计平均TAAS得分显著高于CBT组。
结论：尽管CBT与I-CBT均对强迫症具有治疗效果，但I-CBT在强迫症症状严重程度方面是否不劣于CBT仍无明确结论。不过，I-CBT具备更优的治疗耐受性，可作为强迫症的备选治疗方案供临床参考。