Anxiety disorders constitute the most widespread type of psychiatric disease (Yang et al., 2021), exhibiting a lifetime prevalence rate of 28 % (Kessler et al., 2005). Among them, Generalized Anxiety Disorder (GAD) is particularly prevalent in adults, with rates ranging from 4 % to 7 % (Kessler et al., 2005; Nepon et al., 2010). Individuals with GAD typically experience excessive worry and nervousness, along with an avoidance of both external and internal perceived threats (Craske et al., 2009). This condition is often accompanied by autonomic dysfunction, manifesting as palpitations, dizziness, and insomnia (Craske et al., 2017). Due to its high prevalence, chronic nature, and associated complications, GAD can lead to severe disability (Härter rt al., 2003). The most frequently utilized treatments for GAD include pharmacological interventions and psychotherapy (Kaczkurkin and Foa, 2015; Koen and Stein, 2011). However, even first-line pharmacological agents can cause side effects, especially during the initial two weeks of treatment, potentially reducing patient adherence (Bandelow et al., 2017) and leading to discontinuation of therapy. Moreover, it is not uncommon for psychotherapy to produce negative effects (Scott and Young, 2016) and to be ineffective for some individuals (Stein and Sareen, 2015).

Non-invasive brain stimulation (NIBS) therapies are gradually being recognized as a promising alternative or additional treatment option for GAD (Mutz et al., 2018). Characterized by its safety, few adverse effects, and good tolerability, NIBS offers promising applications (Cirillo et al., 2019; de Lima et al., 2019). These techniques including transcranial direct current stimulation (tDCS) as well as repetitive transcranial magnetic stimulation (rTMS), recent technological developments have introduced variants of traditional rTMS protocols, such as deep TMS (dTMS) or theta burst stimulation (TBS).

The clinical effectiveness of NIBS for the treatment of GAD has been assessed in earlier meta-analyses or systematic reviews (Cirillo et al., 2019; Parikh et al., 2022; Sagliano et al., 2019; Vicario et al., 2019), however, these reviews (Cirillo et al., 2019; Parikh et al., 2022) have predominantly focused on single treatment options, offering limited insight into the comprehensive advantages and disadvantages of NIBS treatments as a whole. Although some studies (Sagliano et al., 2019; Vicario et al., 2019) have included more than one treatment option, they lack quantitative comparisons of the efficacy of different treatments. Moreover, there was a notable absence of comparisons across multiple levels and a full range of treatment modalities, leaving decision-makers without robust theoretical support for selecting the most effective and acceptable treatment options. In contrast, network meta-analyses allow for both direct and indirect comparisons of treatments (Salanti, 2012), thereby elucidating the relative merits of multiple interventions in a way that traditional pairwise meta-analyses cannot achieve. Our study also evaluates the acceptability of NIBS, providing multidimensional evidence to support optimized clinical decision-making. Given these strengths, network meta-analyses should be considered the highest level of evidence in clinical guidelines (Leucht et al., 2016). To date, no study has conducted a network meta-analysis of NIBS treatments for GAD. Therefore, we conducted this systematic review and network meta-analysis to more comprehensively assess the efficacy and acceptability of NIBS for treating GAD.