Repetitive negative thinking (RNT) has been associated with the onset and maintenance of emotional disorders, including social anxiety disorder (SAD). Although RNT has been directly targeted in some treatments, its impact on clinical outcomes remains unclear. This systematic review aimed to evaluate the efficacy of focused (directly targeting RNT) and non-focused psychological interventions on RNT for treating SAD. PubMed, ProQuest, APA PsycArticles, Web of Science, and Scopus were searched through October 2023. Eligible studies were randomized controlled trials of psychological interventions for social anxiety in adults that implemented either RNT-focused or non–RNT-focused treatments. Risk of bias was assessed using the Cochrane RoB 2 tool. Thirteen randomized controlled trials (RCTs), comprising 791 participants, were reviewed following PRISMA guidelines and Cochrane recommendations, with the certainty of evidence assessed using the GRADE framework. While some studies reported symptom reductions, particularly in longer-duration non-focused interventions incorporating cognitive-behavioral therapy, exposure, and mindfulness, the overall certainty of the evidence was rated as very low. A pervasive high risk of bias across all evaluated trials, coupled with severe statistical imprecision and substantial methodological heterogeneity, strictly precludes drawing definitive comparative claims. Consequently, the current evidence base does not support the superiority of either approach. Future research must prioritize rigorous, low-risk-of-bias RCTs to accurately assess comparative efficacy, determine optimal treatment durations, and enhance the overall quality of evidence.

This study was pre-registered in the International prospective register of systematic reviews PROSPERO (CRD42023462842) prior to initiating the systematic review.