A roadmap for focused ultrasound applications in psychiatry: Proceedings of the 2024 symposium on focused ultrasound in psychiatry (FUS-PULSE).

Transcranial focused ultrasound (FUS) is an emerging neuromodulation modality that enables incisionless, spatially precise targeting of deep brain structures implicated in neuropsychiatric conditions. Growing clinical applications in FUS psychiatry encompass both transient and permanent bioeffects, including focal lesioning, neurostimulation, and targeted drug delivery. In response to rapid advances in the field, an in-person multidisciplinary symposium, FUS-PULSE, was held in Toronto, Canada from June 5-7 2024. The meeting convened over 70 international experts across neurosurgery, psychiatry, neurology, psychology, radiology, neuroimaging, physics, and industry to evaluate critical challenges and chart a strategic path forward for the field of FUS psychiatry. Key themes from FUS-PULSE are highlighted, including the need to integrate circuit-based precision psychiatry, navigating the evolving landscape of FUS devices and parameters, and advancing clinical applications across lesioning, neuromodulation, and drug delivery. FUS-based interventions can complement existing behavioral, pharmacological and neuromodulatory treatments to expand options for patients with refractory psychiatric conditions. However, significant barriers remain in optimizing the technology including treatment parameters and developing clinical protocols. The field must prioritize standardized reporting methodologies, protocol harmonization and real-time monitoring of target engagement. High-intensity FUS lesioning, particularly targeting the anterior limb of the internal capsule, shows promise for major depressive disorder and obsessive-compulsive disorder. Advancements in microbubble-assisted lesioning techniques and target mapping for optimal clinical response will further expand targeting possibilities and improve treatment efficacy. FUS neuromodulation and drug delivery applications remain at an early stage of development with promising potential. A deeper understanding of bioeffects across devices, parameters, and brain targets will be critical for successful clinical translation.