Can New Stimulation Approach Ease Depression?

Electrical orbitofrontal cortex stimulation boosts mood in epilepsy patients.

Direct intracranial electrical stimulation of the orbitofrontal cortex (the part of the brain right behind your eyes) produced acute mood improvement in a small study of epilepsy patients with moderate-to-severe depression, researchers reported.

The stimulation, applied with implanted electrodes in patients being evaluated for epilepsy surgery, appeared to modulate mood-related circuitry and may point to a new target with therapeutic potential that may extend beyond patients with epilepsy, according to Edward Chang, MD, of the University of California San Francisco and co-authors, writing online in Current Biology.

“Depression is a common co-morbidity among those with epilepsy,” said co-author Heather Dawes, PhD, also of University of California San Francisco. “The reasons for this are not well understood, and it remains to be seen whether there are any real differences in the forms of depression that occur in patients with epilepsy and those without,” she told MedPage Today.

“If the biological underpinnings of depression in patients with and without epilepsy are the same or similar, then it may be that certain interventions may be effective for treating depression in both groups of patients,” she noted.

Hypotheses about brain chemical imbalances in mood disorders have sparked interest in selective neural network modulation with deep brain stimulation (DBS) in recent years. Well-studied targets for DBS in treatment-resistant depression include the subgenual cingulate cortex and subcortical structures, but results have been inconclusive.

A significant challenge is that mood disorders are heterogeneous and can involve dysfunction in cognitive, affective, and reward systems. “The orbitofrontal cortex has been called one of the least understood regions in the brain, but it is richly connected to various brain structures linked to mood, depression, and decision making, making it very well positioned to coordinate activity between emotion and cognition,” Chang said in a statement.

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