Decision-making for non-invasive neuromodulation prescription in the treatment of generalized anxiety disorder: a roadmap proposal

INTRODUCTION: Non-invasive brain stimulation (NIBS) has been used in the treatment of generalized anxiety disorder (GAD). However, the diversity of protocols, indications, and target populations requires careful standardization to ensure safety, efficacy, and uniformity in clinical practice based on the best available evidence, professional experience, and patient preferences. OBJECTIVE: To develop a clinical decision-making tree to standardize approaches and facilitate prescriptions by healthcare professionals regarding the use of NIBS to treat GAD. METHODOLOGY: Clinical reasoning study based on a roadmap for developing a decision-making tree. After reviewing the best evidence on the topic, five systematic reviews with meta-analyses were selected, from which randomized clinical trials with the largest effect sizes were extracted. From these trials, specific protocols were chosen and presented to researchers and clinical specialists in the field who, by consensus, constructed the clinical decision-making tree. The tools used to assess GAD symptoms in the studies were evaluated, identifying the most suitable ones for the Brazilian population, with recommendations on the best assessment instruments. The tree was presented to other specialists who validated the protocol recommendations. RESULTS: Four protocols were selected as interventions that could be recommended in clinical practice. The protocol with the largest effect size was not chosen as the first option due to the number of pulses exceeding the established safety criteria and the report of a tonic-clonic seizure as an adverse effect of stimulation. Three repetitive magnetic stimulation protocols presented equivalent effect sizes, but continuous Theta Burst stimulation to the right dorsolateral prefrontal cortex was chosen as the first indication because, in addition to having the largest effect size, it is an accelerated protocol, reducing application time, which impacts cost-effectiveness. CONCLUSION: The clinical reasoning process identified three instruments for outcome assessment and four transcranial magnetic stimulation protocol options for the treatment of GAD.