Depression is becoming the leading cause of disability in many countries. Transcranial magnetic stimulation (TMS) targeting the dorsolateral prefrontal cortex (DLPFC) is an established treatment for depression. However, long-term remission is achieved in only a minority of patients.
TMS induces neuronal activity in localized cortical regions, which then propagates through connected brain networks. The DLPFC, however, consists of multiple subregions, each with distinct connectivity patterns. It remains largely unclear which specific connections should be targeted—and how best to stimulate them (e.g., at what frequencies and intensities)—to optimize treatment outcomes. Similarly, our ability to predict which patients are most likely to benefit from TMS is still limited.
Addressing these questions could enable more effective and personalized treatments. To this end, we are conducting clinical trials with patients referred to the TMS treatment program at the Helsinki and Uusimaa psychiatric services. We are developing and testing new treatment protocols, and using advanced brain imaging methods—including MRI and MEG—to improve targeting, enhance outcome prediction, and deepen our understanding of the brain-level mechanisms underlying successful treatment.