When depression persists through medication, therapy, and even ECT or TMS, modulating the brain's mood circuits is an option for the most severe, refractory illness.
Major depressive disorder is among the leading causes of disability worldwide. In treatment-resistant depression, severe symptoms persist despite well-conducted treatment. It is increasingly understood as dysfunction across mood-regulating networks, with the subgenual cingulate (an area sometimes called Area 25), the prefrontal cortex, and the reward system all implicated, and an overactive "default-mode" network. Surgery aims to rebalance activity in this circuit.
Surgical options are considered only after multiple medications, evidence-based psychotherapy, and usually electroconvulsive therapy (ECT) and/or transcranial magnetic stimulation (TMS) have been tried without lasting benefit. As with all psychiatric neurosurgery, candidacy is decided by a multidisciplinary team.
Several of these options are investigational and are offered within careful oversight. Benefit often develops gradually rather than overnight, and treatment is always paired with continued psychiatric care. The aim is meaningful, durable relief and a return of function, tracked with standardized rating scales.